It did end on a cliffhanger, so I'm not sure if there was truly proper closure, particularly for the Krista Star character. I don't think it got proper closure. The series takes place after the film, but its not clear when, so I would say its a loose continuation. There was a reference to Sommerfield, the blind Nightstalker from Trinity, but Blade no longer uses the serum inhaler, he has gone back to the serum injections from the first film and that's not explained. There is no mention of the Daystar virus and why it failed to kill off the vamps. I can't remember if Abigail Whistler, Hannibal King, Deacon Frost, Damaskinos, Nomak, the reapers, or Drake were ever mentioned in the series, but I don't recall them being brought up. Blade's parents, his mother Vanessa from the first film do come up. The series also had some continuity issues with the first Blade film regarding how Whistler and Blade first met, but I don't think its something that's major. The vampire houses introduced in the first Blade film are a major focus of the series. One thing that bothered me initially was that I felt Blade was depowered, but I chalk that up to the change in actors because they never mention him being depowered, though he does require help identifying vamps in the series and he never had a problem with that in the movies.
After saying all that I do recommend it. Its not as good as Blade 1 or 2, but I thought it was better than Blade Trinity. I'm of the opinion that it was Jill Wagner's show (Krista Star) instead of Blade's. However, there were a couple good Blade character moments sprinkled throughout the series and Kirk Jones (Blade) grew more into the role as the series progressed, however he was no where close to being the dynamic action star/martial artist that Wesley Snipes was. If you liked the vampire houses from the first Blade film then you'll like this show, because it expands on that. Plus it adds some interesting villains to the Blade universe. It's a shame Spike cancelled it.