Servers are getting older, so there is much less profit producing items with a craft (ie: tailoring, leather). If you plan to join a guild of even a relatively small size, chances are most professions are covered already. You would do better as a gatherer to a) help guildmates with their professions and b) make money for yourself.
What's the point in having two people overlapping their trades? It's generally a waste of resources. The exception is this: Lots of patterns require large amounts of mooncloth, or cured rugged hides even. These can only be made once every 4 days, and are in demand by guilds. I think our guild has 10 people churning out mooncloth now, and we still never have enough for bags and armor.
Mooncloth sells on the AH for ~15g on my server, if you really wanted to sell it there's guaranteed profit there.
Otherwise, you're in good shape with two gathering professions. I do it with my alts, and am quite satisfied with the results. Rugged leather is in higher demand on AH because people are using it in large quantities to run Dire Maul. Dragonscales sell for a pretty penny, especially black and red. End-game mining also produces a fair amount of money I hear, although I haven't gotten there yet myself.