Just the opposite, actually. Dark Horse is releasing at least 3 more Omnibus volumes (collecting the Further Adventures comic series and the film adaptations), and at least another volume in the Indiana Jones Adventures series. It seems they're keeping the Indy stories coming out on a regular basis, probably as a cross promotion type thing for when the Staff of Kings videogame is released late next year. I'm sure around that time you'll see A LOT of related Indy comics, novels, etc.
Keep your eyes peeled, 2009 will be a big year for Indy releases, including new comics.