Assuming that all users were active online at the same time, this would give each one an effective 83.3kbps connection -- 50% faster than a 56k modem. By "active" I mean actually loading pages or downloading stuff simultaneaously. I also assume you meant 1Mbps (megabits), and not 1MBps (megabytes), as that is non-standard nomenclature and would be equivalent 8Mbps.

I doubt you'll have any problems, except when everyone goes to download the latest IE security patch at the same time.

Jim