We are on-track to deliver SP1 in mid-summer 2011 (here is the official announcement). We definitely recommend this update for all Office 2010 users. If you’re one of the few 64-bit Access users working with compiled Access databases (ACCDE, MDE, and ADE files), be sure to check out this KB article that details an update process you’ll need to go through to have your files work properly with SP1.