I backed up the home directory , took images of the partitions involved using dd . So that I would be safe in case of surprises.
These are the various issues I had with FC6 .
Google toolbar would not download , sticky-notes applet did not read my older notes , Tomboy notes also would not read the older notes . My favourite was a Stock ticker in the panel this was replaced by something called invest which also does not work . I was actually using the computer for various things including maintaining a website.
So I wonder how others fared and what are the work arounds these problems . Not only that it would boot into the terminal screen and not GUI .
So now I will carefully put FC5 back . One thing that beats FC5 is the 3D screen background .
Actually I am going to wait a few days before actually restoring FC5.
The two things I want to get back are :
1. Tom Boy notes
2. The Stock ticker

I had some problems with FC6 as well. I used to use FC5 on my computer, and then my dad wanted it on his computer, so he downloaded FC6 and wanted me to install it. It was buggy like crazy. The release is very new so maybe you should wait a while until they get the bugs worked out of it. Maybe I'm just weird but I usually stay a version behind just so I know I'm not going to have too many issues.

Completely agree . However I read some very good feedback so decided to go ahead . By the way saving the images and the MBR worked . I had FC5 running in an hour and a half . Then I got back to FC6 there is so much to do in new version . . Will get back to FC5 when I feel I have had enough.

I had the problem of not booting into the GUI . It started booting OK . Now it is back to the text mode.

anilbh: I like the way you handles the old version of your system. I have done the similar thing on my image server and my FC6 seems to work just fine except for NetworkManager. (FYI, my FC6 is installed on my laptop) I mean that it works and my wireless connections should be established at any wireless available areas. On FC5, it worked pretty well and I did not have to do any extra work to get internet connection but FC6 seems to demand my some extra works pretty often. :-(

My old([FC4] and FC5) Tomboy notes and stick notes are all available on FC6 but I can not tell anything about Stock ticker because I have not used it at any old version.
(All of sudden, I thought it may be "SELinux". Is your SELinux enabled? If so, can you disable it or set it as "permissive"? It may help.)

BTW, your text mode login may happen if
1) your /etc/initab is somehow screwed up to setup with init 3.
2) your xfs daemon is not running.
So, I would check to see what the runlevel is on /etc/inittab and look for anything suspicous /var/log/{messages,Xorg.0.log} if anything is recorded there.

Thanks Narut,
I am writing this on FC6 . I am continuing the updates etc.
I think I tried disabling Selinux . Mainly to get HPLIP working correctly - no lock .
The text prompt now disappears after a few seconds.
So I am will still use FC5 until I am satisfied with this.

Anil