looking to get a new stang but was wondering
 

when is Ford planning to change the style of the Stang? I have a 2000 and was thinking of getting a GT 03 model but if Ford is going to radically change the design soon after(line in 04) I want to wait till the new design. Also what will be the differences from the 02 GT to the 03 GT? Thanks for your help.

The all new Mustang will be released in 2004 as a 2005 model. Ford had originally wanted to bring it out in 2003 as a 2004 model, but has since backed up the production schedule.
Doubt there will be any difference in '02 and '03 GT's. The main foucus seems to be on the new 390HP Cobra and possibly a MAch 1 version.

where could I go (on the web) to see what changes are being planed for the "all new" 05 mustang?

You can't go anywhere. Nobody knows what is really coming, and some have only made educated guesses.

There are so many rumors flying around about the SI-97 'Stang. Nobody knows anything for sure but Motortrend did a story on the Next-Gen Mustang/Camaro last summer and it talked about possible features of the new Mustang.