There was talk of this a few months ago, but there's always talk of sequels to everything. Snipes is perfect for this role, and it would be crazy to recast, but crazy is the film industry's middle name, so who knows. With vampire-mania still fairly strong and the comic-based films dominating the box office, another Blade seems inevitable.
I liked the 1st two films (the less said about the 3d the better--it was fun but completely stupid), so get a real script, give Snipes the weapons, and let him do his thing.