You'll get a lot of "Go BM" responses, just to warn you.
Beast Mastery has unfortunately over-stepped marksman for top DPS,
but I've never been able to get used to it. Marksman is still a decent spec and is good for arena, etc... which I'd definitely reccomend doing to get some upgrades (although I've been lazy and haven't done it myself). Other than that, heroics are a good way to start getting some better gear
I'm not sure about the skinning versus farming motes thing, but I can tell you that on my server (PVP) I don't really even think too much about farming them... lol. I am a skinner/LW, and knothide/heavy knothide still seem to sell decently well.
If you were planning on raiding, I'd tell you to go SV or BM.... but if you're doing solo, arena, and some 5-mans, for the love of pete do what you enjoy and stay marksman (that is, unless you like BM better). You'll still
do good damage, have good solo capability, and do well in PVP (scatter and silence ftw!).
Anyway, I hope this (70 troll Hunter, blackrock) SV
--Penance (70 Blackwind Sabrecat)
--Seraph (62 Ghost Wolf)
--StoneGmork (57 worg)