Yes, there will definitely be future SWSE books...
Things that already have titles and you can find at Amazon
Starships of the Galaxy (December 2007) -- lots of starships, rules for making new ones and customizing existing ones, advanced starship combat rules, and some player stuff too
Force Unleashed Campaign Guide (March 2008) -- basically a campaign setting for the period between Episode III and IV, before the Rebellion really got going; some tie-ins to the video game of the same name
Threats of the Galaxy (May 2008) -- Bad guys and monsters of the SW universe
There are also two sets of Galaxy Tiles (Dungeon Tiles for Star Wars) and a character sheets/GM screen pack on the schedule.
Thing that's been mentioned by WotC people but hasn't been titled or dated yet
'A book about the oldest knights of the Republic' -- i.e. the long-awaited KotOR/Tales of the Jedi era book
Also, the Dawn of Defiance mega-adventure will be available on WotC's web site, with one chapter a month starting in November or December (and it's about 320 pages total). And I think I read somewhere that they're planning on 4-6 products a year.
