The current description of the new software states that it only provides "Bug fixes". Hopefully it will rectify some of the issues experienced with 2.0.
We will update you with further information once it becomes available. If you have pwned your iPhone please do not update until a working method is revealed.
Update: Had a chance to use the new 2.0.1 software on my 3G. I have to say, there is a really nice improvement in speed. My contacts don't take "30 seconds" to load and it isn't slow when trying to scroll through them as well. The push feature has been improved in that aspect. Also the load times seem faster for the programs. May just be us. Let us know in the comments!