assuming you have alch as one
engineering, inscription, tailoring, jc (depending on class) or enchanting are viable
engineering can be great - you get a nice dragonling trinket, and plenty of tinkers. if the helms ever got lowered to 80 thatd be nuts too. not to mention the bombs and other fun gadgets
inscription gives you sweet shoulder enchants, much better than the hodir or wintergrasp ones
tailoring has great cloak enchants
jc can be good if you have 3 cata gem slots available, they're getting buffed in 4.3 for when epic gems are released too i believe. even better if youre 81+ for the jc trinkets.
enchantings got ring enchants still, afaik, which are nice
leatherworking still gives you the sweet wrist enchants which arent too bad paired with regular cata leg enchants. up to you though. i would say engineering and alch is a great combo, engineering just has so many things to offer from belt and glove tinkers, rocket boots & flexweave underlays, bombs, etc. not sure the inscrip enchants make up for that, or if any of the other profs are as good. just comes down to personal pref i guess