I can't see Luke ever being more than a fill-in starter, but I don't see why he can't kick around the league as something liek a poor-man's Ryan Gomes/rich-man's Brian Scalabrine. He's shown, at least in the summer league, that he's got 3-point range on his shot, and that he was able to get it off despite its awkward form. He's not really big enough to be a full-time PF, but he hustles after rebounds enough where he should be able to fill in a bit there. The question is whether he can play decent enough defense, at least team defense.
The immediate comparison is obvious, so forget that. If Gody can play team D as well as Scal (meaning, good enough to not kill the team when he's on the floor), how is he not Scal II? OK jump shot, a guy who's always going to hustle in practice, kind of able to fill in at a couple positions.
So I think Luke *can* find a niche in the league... but the Euro leagues and D-League and Chinese leagues and every other non-NBA league is filled with guys like this, too. There's absolutely an element of luck in terms of which fringe players like this make it, and which do not.