"The Big Deal" for me with Leatherworking is looking ahead to WotLK. The grind from 1->375 is a one-time cost, while all the PvP items you earn today will be very quickly obsolete at L80. Yes, skilling up to the new cap and creating the new gear will be expensive, but it's something that can be easily done in quest greens and blues at L80. Farming the new heroics will be much more challenging in those greens and blues.
Furthermore, go compare the Netherstrike gear to the original S1 gear, I'd suggest comparing it to the original badge gear but there wasn't any good pieces

http://www.wowhead.com/?item=27469 vs http://www.wowhead.com/?item=29519

Not only is Netherstrike better for PvE by a good margin, I guarantee you that you can get the L80 LW gear faster than the L80 Arena gear, and likely faster than L80 PvP gear if you prepare now for it. It's around 3 months to the estimated release date... if you farmed gold a few hours a week between now and then you'd have more than enough likely to buy your way up to the new LW cap and get your epics. You could possibly do the same with PvP by banking a bunch of honor, I am not sure...