Many different paper deadlines are coming up soon so I made a little reference table. Out of curiosity, I also computed the interval between submission deadline and conference.
|COLT||Pittsburgh||June 22-25||January 21||152|
|ICML||Pittsburgh||June 26-28||January 30/February 6||140|
|UAI||MIT||July 13-16||March 9/March 16||119|
|AAAI||Boston||July 16-20||February 16/21||145|
|KDD||Philadelphia||August 23-26||March 3/March 10||166|
It looks like the northeastern US is the big winner as far as location this year.