According to Boy Genius Report, the new update will mean:
- Baseband updates for the 3GS and iPad (original)
- Fixed memory hang that results in memory corruption when reading large files from USIM file system
- Fixed problem with NTLM authentication in apps and on websites
- Fixed issue with the Springboard and third party apps not recognizing the gyroscope on the iPad 2
- Fixed iPad 2 jailbreak vulnerability
The fix will make Apple devices work smoother, but also protect the iPad 2 from jailbreaking -- something much needed since it was hacked a mere 24 hours after it was launched.
However, remember that this is only a rumor and has yet to be confirmed by Apple.