OK guys, I got 2.0 on my 2.5G iPhone, WONDERFUL!!!
So here is a little guide for those having issues:
*** 1st rule - You must back-up your data, then restore to 1.1.x***
*** 2nd rule - Download firmware 2.0 from here:
http://gizmodo.com/5023760/download-20-firmware-for-any-iphone-right-now You will see a link titled "Here" on this web page, make sure you right click the link and select "Download linked File AS". Save to your desktop. Once the file is downloaded, remove the .zip extension until all you have left is .ipsw, select the accept .ipsw extension window. ***
*** This worked perfectly for me, however, proceed at your own risk, especially if you're not savvy with computers or tech devices. I am not responsible if you have issues with your iPhone. This guide is simply there to help those who can't stand the wait and know what they're doing***
This is only for people with "Hacked" or stock iPhones, NOT "Unlocked" iPhones. Trying this with an unlocked iPhone will brick your phone. YOU HAVE BEEN WARNED!!!
1. After you have a clean restored 1.1.x image, complete your back-up or at least get 1/4 to 1/2 way into it or you will get errors (Unknown error [1] for example).
2. If you don't want to complete the whole back up, stop your backup at about 1/4 to 1/2 way through, hold the option key, select Restore.
3. Now select the file you downloaded and renamed above.
4. Sit back and do something as it will take a while to complete the upgrade
5. Restore from the back up you made earlier
6. Enjoy!