What is the patch about?
Its main goal is to address stability problems with the game and performance issues. It is not intended to address game logic fixes.
You are being vague. Exact changelist please!
Removed some memory leaks
Fixed crashes when the game attempted to render lots of content (high detail, high FOV or multiple-monitor modes); this should particularly help multi-monitor users
Chat window no longer causes lag spikes
Chat window reworked opacity & visibility-time is controllable through settings in settings.ini
Clantag is remembered when using auto-login
Banner URLs can be up to 252 characters in length
SecuROM wrapper removed from non-Steam version
Minor performance enhancements
Reduced rubberbanding on servers with more than 24 active players
PrintScreen takes a screenshot, file stored in Documents\BFBC2\Screenshots directory
How large is the patch?
It is approximately 2.6GB.
That's huge man. Given that size, I would expect dinosaur survival mode to be included.
The patch itself contains all previous patches rolled into one. While it would have been technically possible to create a smaller patch for those who have Client R10 installed already, that would have delayed the release of the patch even further - so we thought it better to release a larger patch now, than a smaller patch sometime in the future.
Are there any known problems with it?
If your Windows username contains non-English characters (such as ?, ?, etc) then PunkBuster will not activate properly. To work around this, ensure that your Windows username uses only characters from the English character set. In other words, "7-bit ASCII only, please". We caught this at the very end of the validation pass, and decided that it was better to deliver the build to the public than to give it another tour through the whole patch generation and validation process.