Betsy Riley, and SC09 committee member, posted some unofficial stats on attendance at SC09 this year in response to a LinkedIn question. I’ve gotten a few emails about this, so I’m re-posting her answer here

all registrations: 10,189
tech program: 4,032
exhibitor: 3,491
exhibits only: 533 (plus 1,723 guests)
71 countries represented, all 50 states plus Puerto Rico and DC

318 exhibiting companies using 131,650 sq. feet of exhibit space
123 research exhibitors (new all-time record)
195 Industry exhibitors
largest booth ever: Microsoft, 4,500 sq. ft.

tech papers: 261 submissions, 1100 reviews, 59 accepted (22.6%)
tutorials: 28 accepted out of 71 submissions
29 panel submissions (more than twice that of SC08)

These are still only semi-official. They still have to validate the numbers (checking the list to remove duplicate registrations).
We had 95+ press badges picked up–an all time high.