Well, I've gone and done it. I've had a $100 GC to TRU in my pocket since Christmas and since my local TRU hasn't stock anything of interest since then, I haven't spent it yet. Made a trip after work with the boy to kill time before heading home and they actually had all of wave 1 (one of each plus the extra Batmen). My apprehension of buying them lasted about 2 seconds. I figured what the hell, I'm not going to use the GC on anything else soon.
I'm going to try and be selective with this line but I really like the BAFs shown so far (especially Grundy), so I'll get most of wave 2 and 3 (I'll try to track down the piece from the Electric Supes separately but I have a feeling most people will be buying that figure just for Grodd's part).
I guess the next question to ask is what older figures should I try to track down? Supes I'm not too worried about, you know he's coming again. Two-face (who I've never even seen), Clayface (pissed that I passed on him multiple times) and Catwoman (ditto) are probably tops for me as I'm more of a Batman fan than a Superman fan (although I wouldn't mind having the blue Supergirl or Steel).
This might not be a bad decision though. Marvel stuff isn't looking all that hot this year and I got most of what I wanted from them character wise, I could just switch to a new universe.
(Yeah, that'll be what I keep telling myself). 
Welcome aboard Mikey. Its nice to see there's another
sucker convert among us. I'm in the same boat as you, as I originally was just going to get the Batman-related figures, then the Justice Leaguers, and now I feel like I want to get more of them. Like you, I'd like to get the Wave 2 (Grodd) and 3 (Grundy) BAFs, so I may end up buying a couple figures I normally wouldn't have just to do that. Also, like you mentioned, I'm pretty happy with the Marvel lineup we have at this point, so hopefully the "funds" can just be switched over to DCUC. I'm interested to see what Toy Fair will show us is coming from the Marvel line(s), so then I'll have a little better idea. Also, although I really like them both, I really feel like I should choose between the DCUC and GI Joe 25th lines. Budget and space is at a premium, and I really should just do one or the other. Like I've said before, there's just too much good stuff out these days. At least Joe is somewhat affordable, and after a few more figures/characters I could probably be happy with what I have (maybe...hopefully). We'll see.
I have to say, the Cassandra Cain Batgirl is the one figure I don't think I've ever seen at retail. Its ok I guess, since I was more interested in the Barbara Gordon version from the two packs, which came - and went - and then came back again (I grabbed it on clearance for like $7 or something). It seems like there are a few people wanting to backtrack with the DCSH line now, so hopefully it won't be too much trouble for them. Around here, they are all but dried up, aside from a couple Batmen at TRU from the last wave I believe. There were really some nice figures in DCSH, including ones mentioned already (Clayface, Catwoman), and a few others (Luthor, Darkseid, Mongul).