I heard by email yesterday that SC has extended a few deadlines until this Monday; here’s what I know
SC10′s submission deadline for posters, including entries for the ACM Student Research Competition, has been extended until Monday, July 26. Students entering the ACM Student Research Competition should take care that their entries target the “ACM Student Poster” submission category. Submissions complete by the original deadline may be edited until July 26 at midnight EDT; reviews will be returned to submitters on or around August 16. Please send any questions to firstname.lastname@example.org. More info: http://sc10.supercomputing.org/?pg=posters.html.