Trek's site has an archive where you can view past models
http://www.trekbikes.com/us/en/bikes/2007/archive/
[edit] Based on a quick glace, it appears that the SU 1.0 is a slightly cheaper bike (than the SU100). They've downgraded a few components slightly - front derailleur, seatpost, seat, pedals, maybe a few more. Nothing drastic.