
The new exciting patch is currently in testing and it is LIVE! The PTR is ONLINE, restart your StarCraft 2 to get your gamefiles. Run the StarCraft II Public Test.exe in your Starcraft II folder to launch the client. It is approximately 100mb.
There are many new exciting things happening in the new 1.2.0 patch (expected late December early January). A huge list of balance changes, bug fixes and features are documented and are being tested as you read this.
The first awesome feature that has been added is the new Chat Channel system (as seen in the picture above), here you can have up to 100 players on any given channel. This will ensure a proper discussion between clan mates, friends or foes alike.
Hotkeys can be changed to suit your playstyle - although it take some getting use to, this feature is definetely haven for some. A page of all the units, abilities, upgrades and even commands is shown and here you can select the hotkey you desire.

Another cool feature added is the Vespene Worker count. Whenever you click on a Refinery/Assimilator or Extractor, you can see exactly how many workers you have assigned to that particular structure.

This will definitely help people out whether they are over-saturating their Geyser or not.
The pause screen will also be changed and will ensure no unneccesary surrendering.

There has been a huge cry for Blizzard to add new maps and that they dide. However, they only added one map and that map hails from Warcraft 3. Behold StarCraft II's Plunder Isle.

And to top the list of balance changes, this change will ensure no sneaky tactics to block a poor Zerg's economy off. The ramp mapping will be modified.

I'm sure you have many questions as to what is going on. So here is the official FAQ, neatly documented for yourself.
You may be familiar with the idea of public tests or a "PTR" from playing other Blizzard Entertainment games. If not, you can think of them as open beta tests where players can preview upcoming patches before they go live. Patch 1.2 marks the first time that we've performed a public test for a StarCraft II patch, but we're planning to conduct public tests for most if not all future game patches. These PTRs help us a great deal -- when you participate and submit reports, we can squash more bugs and ensure that when the patch is released it's of the highest quality possible.
Q: What is the Public Test Region?
A: The Public Test Region, or PTR, is a way for us to invite you to help us test upcoming patches, as well as offer feedback on proposed changes, before the patches go live. You can think of them as open beta tests for patches. We've used the PTR system for many years with World of Warcraft and have seen great success in improving patches by inviting players to come play, report bugs, and let us know what they think of the changes before they're implemented on the live game.
Q: Who can participate on the Test Region?
A: For the current phase of PTR, we've selected players with these criteria:
* The player has had an active StarCraft II North America game account before 11/11/10.
* The player's account is not a guest pass account, and is not suspended or banned.
Q: Are there plans to allow players from other regions to participate in the PTR, and will they have their own regional PTR?
A: We would like to eventually open PTR access to players in other regions. However, we are currently working out the details and there is no ETA for when this may happen.
Q: How do I participate in the PTR?
A: When the PTR is available, a retail patch will add a new executable file named “StarCraft II Public Test.exe” to the StarCraft II game directory. To access the PTR, go to the StarCraft II game directory and run the “StarCraft II Public Test.exe” executable.
A small patch will be downloaded to install the PTR client the first time you run it. Eligible accounts will already be enabled for the PTR so there's no sign-up needed for this phase of the PTR.
Q: Can I still play the retail game after I install the PTR version?
A: Yes. The PTR data is stored separately from your primary game data, so you can continue to play the retail version of StarCraft II by running "StarCraft II.exe", or you can play the PTR version at any time by running "StarCraft II Public Test.exe" instead.
Q: Where can I send bugs or feedback about the PTR?
A: Whenever a PTR is available, this Forum will appear for you to provide us information on bugs, feedback, and/or suggestions. The forum is monitored by our QA department. Due to the nature of this forum, it will be moderated fairly heavily to ensure the information posted remains constructive and useful for testing purposes.
Q: Can I copy my character, and does my Test Region character stay from each PTR phase to another?
A: No, character copy is not available to the PTR.
There may be times where we wipe all character data after or during a test period to facilitate specific testing we may need.
Q: Do my friends list, achievements, campaign progress and ladder ranking carry over to PTR or vice versa?
A: No, the PTR is separate from the retail regions. None of the character data will transfer from retail to PTR. Additionally chat between PTR and retail regions will not be possible.
Q: Will the PTR also have full customer support available?
A: No. The PTR is mainly for testing purposes, so support will be very limited. However, we will still take appropriate action if players violate the TOS and/or EULA.
Q: Can I publish maps to the PTR? Is there a PTR editor?
A: At this time, we are not including the StarCraft II Editor as part of the PTR process. There will be no player created maps on PTR.
Q: How long is the Test Region going to be open?
A: There's no predetermined period of time the PTR will be available. It will remain active until we feel the patch has been appropriately tested.
Q: How do I uninstall the PTR version of the game?
A: There's no need to delete the files because the PTR data is separate from the retail game and won't affect your retail experience. If you want to do so anyway, you can delete the "\VersionsTest" folder in your StarCraft II game directory. Future retail patches may also automatically uninstall the PTR version of the game if the PTR is no longer active.
Please Visit the Forums for the Official Patch Notes in progress.