Yeah, I think distribution continues to be a big problem for Mattel (at least around here). Granted, I did see Wave 3 (except for Nightwing) at our local Target yesterday - but I had already gotten a set online. Otherwise, Wave 2 came and went quite quickly (and only at TRU) around here, and Wave 1 seems to have a few figures still on the pegs here and there (usually Red Tornado and Etrigan it seems). I don't mind ordering a set of a wave online if I want basically the whole lineup (like Wave 3), but like I mentioned earlier I'm trying to get more selective with what I buy, this line in particular. I really want the WW from Wave 4, and wouldn't mind having Cyborg and Batman Beyond as well - but I just can't bring myself to order a $70 (plus shipping) set online to get those three figures. It looks like waves in 2009 and forward it might be easier to order individual figures (I hope), so that might eliminate the problem.
If I had to rely on retail for this line (or the previous DCSH line), I'd be out of luck I think. I can't imagine how "casual buyers" who may not visit stores 1-3 times a week (like many of us do) would have any hope of finding the majority of what they want - but that goes for a lot of lines these days. There's just so much stuff out there, and the turnover between waves is so quick, its often "blink and you miss it" with a lot of lines - Star Wars included sometimes. I miss the "good old days", where you could - for the most part - walk into a store and pick up almost any character you were looking for.
As a side note, I was just checking BBTS and see that they have single figure orders available (similar to CSC mentioned earlier) for Waves 6 and 7. I've always had very good luck doing business there, if anyone is interested. I wish they had orders for Wave 4 as well, but I think that is before the "online single ordering" policy Mattel has for the upcoming waves.