The rumor mill is full of buzz that Canon will be coming out with a mirrorless eos compatible (well, the eos compatibility is hoped for) camera this summer.

Theoretically, this would be an ideal camera to modify for IR use, right? With a sensor based autofocus and full time live view, you could remove the IR cut filter completely and have a full spectrum camera. Then you could just changed your front element filter and have your choice of wavelengths, with full time auto/manual focus and evf framing capability. I'm assuming that with live-view focusing, the different focusing lengths of VIS and IR wavelengths can be compensated for.

I'm imagining my ideal backpacking all-in-one setup, assuming it records raw and the sensor can handle the startrails shots I like to do.

Hmmm.. the same issue came up when the Sony R1 came out, since it was a CMOS sensor with EVF (it was suppose to be THE camera to have converted, but it had its issues). Its also a different beast from the new Canon-mirrorless rigs, so can't really compare the two. I have a Canon-IR body, its simple to see what's behind the picture after you take it, simply shoot in raw+jpeg and leave the jpeg mode in b/w, and you can see what you get without viewing the all-red image you usually get.

In terms of full-spectrum + IR, I think that would be cool to have, but the IR mode in itself is just a lot of fun to have; I don't see the need to have both! I think the live-view mode of any capable camera would yield the same results as a mirror-less camera, the benefit being you get to see the image you're about to take in full IR with the IR-filter installed. So I think the difference would be minimal between the two rigs. But I could be wrong, either way, IR is fun.