If you mean the current IDW material - Yeah, they collect it in trade. IDW really has an emphasis on collected editions, so everything gets collected, usually multiple times. If you're after info on the IDW stuff, I'm more than happy to help Or ask Arcee. I think she passed the crash course.
If you mean the Marvel stuff - IDW has sorta done it (had to skip the Marvel issues containing marvel characters) and are doing them again (with those issues re-inserted) but the colouring is.....well, it's not for everyone. Some people strongly prefer the Titan tpbs. I personally have both, and I like the matte paper on IDW better, but the colour reproduction on Titan more, so I don't really know how that balances out? At the moment, I'm giving the IDW reprints a fair go, and reading the first volume of US (They're also doing the UK material in Classics too. Some stuff Titan never did, which is great).
I can't wait for Earthforce at full size, colour be damned. (Hopefully they'll leave them black and white, but who knows. That's a way off, anyway).