With Beta 4, you must upgrade to the Beta for iTunes 8.2. The iTunes release is only available to developers, and must be installed to use the forth Beta version of iPhone OS 3.0. Now, I have over 30,000 songs in my iTunes library, and the new version of iTunes must update the library. It took almost 3 hours.
Once that was done, it took another two hours to get my phone configured the way it was before the upgrade to Beta 4. In short, iTunes took forever to configure itself with the Beta release. Once it was done, I must say it is snappier and works quite well. Best I can tell, this pre-release of iTunes is specifically for iPhone/iPod Touch 3.0. There are no other changes that I can see at this time.
As for the iPhone software, it is yet again faster than the previous version of the Beta. Many bugs where fixed in this release, such as the redial button disappearing after you terminate a call. This is a nice fix, as I do a lot of redialing for work related issues. Not much else has changed. Still no MMS. Still no tethering. Everything else is still functional and more things work correctly. No crashes so far since I have been using it for about 24 hours.
Any questions or comments please sound off below.
If you need help getting your UDID activated on a developers account i found the website that i linked to my name above actually found them in facebook, just click on my name to go there. They had me up and running in no time and i now have complete access to their Apple developers account with my own user ID and password. It was worth it, just my 2 cents for anyone who is in the same boat i was.