I'm going to go ahead and say 'very likely,' not simply because it'd be an easy cash grab for EA/BioWare and act as a lead-in for the next Mass Effect. A BioWare developer posted recently on NeoGAF asking what fans would like to see in a trilogy remaster other than the obvious 1080p/60fps. Various ideas were thrown in and while nothing was explicitly confirmed, it's long been rumored and that post solidified my suspicions.
It's a fantastic series and I highly recommend it. A remaster could be worth waiting for if it includes the DLC as there's quite a lot of it for both Mass Effect 2 and Mass Effect 3 and it's all pretty high quality. The PS3 port of the first game is also pretty awful, so if you're intending to play on a Sony console, I'd avoid it if you have the chance.