Some interesting statistics from both Macromedia Flash & Macromedia Shockwave:

Internet Connection Speed Market Share
33.6k or below 3.0%
56k Modem 26.2%
ISDN 0.9%
DSL or Cable Modem 59.2%
T1 or faster network 9.5%
Other/Don't know 1.0%

These are worldwide statistics. There are other interesting stuff on that page. Be sure to check it out!