Bar feral I think you'll find that rogues are the best melee class in arena.
I look forward to ferals getting nerfed, but to say feral is better than rogues or dks (in each of their respective top comps) is folly.
rls/shadowcleave/fmp (I believe these to be the top comps for each of the aforementioned melee classes) are top tier comps, clearly. However which of these is the most 'top tier'? I'd have to say shadowcleave or rls (I'm tempted to say shadowcleave number 1, but whatever), and as a distant 3rd fmp.
I am talking about top of the bracket play, not 2200s, obviously. If you are talking about low rated arena, then yes, feral>rogue>dk. Probably more like Feral>rogue>>>>>>>>>>>>>>>>>>>dk in the <2400 brackets.
One more thing, my somewhat-arbitrarily assigned rating brackets probably need to be adjusted now that the mmr system is so royally screwed up. Seems more like the old 2400 bracket is now the 2k bracket, the old 2200 bracket is now as low as 1800-1900, and the top teams are either not queueing or just have really shiny win/loss ratios at 2500-2600, and no queues when they try to get higher. (This could be the case only for shadowburn/it's bg pool, but I dunno, haven't heard about any good queues in a long time now)