I was going to wait for the light tackle guys to reply, and then offer a discenting "traditionalist" opinion, but since no one replied, I'll start:
It depends on your skill level and the size of the flys, you'll be using. If it's the best rod available, I'd go ahead and use it.
If you stick to small streamers and "panfish-size" bugs, it could work out.
However, the large flys and bushy bass bugs, traditionally used for largemouths, are best fished on a 7 to 9 weight outfit. Especially if you're going to fish in lakes or ponds, where you'll want to make long casts, with large wind resistant flys/bugs.
It's not the size of the fish, but the size of the fly.