They show a bit of Slamball on cable over here in the UK, been watching a fair bit of it lately. I'm pretty sure the stuff they're showing is from 2003 so I'm not sure if the league has moved on from there or not. They've got John Salley, Pat Croche and some girl as the hosts, Xavier McDaniel is a head coach of one of the teams, Kobe Bryant's dad Jellybean used to be (maybe still is) a coach too.
This weekend just been they showed the slam dunk contest along with a series of top 10s from the year, the dunk contest was insane, front flips through the legs, 360 double pump windmill through the legs, the options are so varied, it's genuinely like watching a real life version of that old classic NBA Jam.
The problem with developing the sport is obviously the highly specialised court they play on, also the potential for pretty serious injury means any insurance would an absolute nightmare. They do (did?)have a draft but to be honest I've no idea how this works as it's not a sport with a significant (or any?) lower competition from which to draw players.
From what I can gather most of the players are ex-college ball players not quite able to cut it in the pro leagues, good atheletes with natural flair but poor fundamentals.
While the play it up as being a serious sport with serious competition I think it's a 50/50 mixture between legitimate sport and sensationalised entertainment (for the record pro wrestling comes in at about 5/95 on my scale), but I don't think it's too far removed from the professional dodge-ball they show sometimes (which is hilarious conincedently).
It's undeniably entertaining to watch but after a while you get used to the big dunks and crave a purer form of the game. Nothing produced on the Slamball court can compare with seeing Vince jump over someone with no trampoline.