Currently at diablo inferno. Or rather Shiablo. Pretty hard, but despite still being in crappy gear the rest of act 4 was really easy for my DH, I went through it solo in a few hours. My current assesment of inferno is that for a DH, if you buy a decent bow with 1k+ dps (~700k gold) and some cheap other gear (~300k) that you can do all acts, and the only big problems will be Belial (endboss act 2) and Rakanoth (boss in act 4).