I've been considering switching to one of these 2 professions over my current inscription.
Blacksmithing
New weapons, lots of craftable pieces, sockets for wrists/gloves
or
Leatherworking
Lots of craftable pieces, leg enchants for tanks and AP class, wrist enchant.
Profit-wise they should be similar once u get ur hands on new patterns, as to leg enchants vs belt buckles ud have to check ur server prices. Personaly id go for bs, since the stat bonus is slightly better and it will get even larger once epic gems are introduced.
Well inscription does seem to be winding down in profits, but with the high cost of switching to these professions I'm not sure it'd be worth it in a business only sense.
I mean if this is on a main toon and you've got the materials to make this work once you are max level (Spirits and such) and are sure you'll be able to get your hands on recipes on time in 5.2 it will be worth it. Any profession is worth it to have if you can make sure you are among the first to be able to produce something OR have the ability to stay in a market and keep pounding out sales of things at lower margins. Leatherworking has more different specs and classes it works for (and all the new monks to fit out) so the market is more diverse but also harder to get all recipes for and Blacksmithing let's you concentrate on fewer things, making it cheaper and easier to keep stock but has more competition per item.
On the whole if you do switch, and you're also interested in the stat upgrade side of things, then I'd go with Blacksmithing. Otherwise not much between them to be honest.
The best professions is to not waist your In-game currency on worthless junk!
:O and otherwise lead a level 25 guild and plunder the guild bank, It seems I'm good at that.