Hard to say.
If you like the specific coloration of vocals on the W3000ANV, then no, the TH900 isn't going to be too similar. The midrange on the TH900 is clearer and more transparent sounding by comparison, though it still has a certain special quality to it like the W3000ANV, just different. For me the effect of the W3000ANV here is somewhat akin to a filter, that "antique hue" I'm always on about when I mention it. To my ears it's more sultry, romantic, ambient, hypnotic, and heavy-lidded. Like sitting in a smoke filled nightclub or an opium den. The TH900's presentation of vocals on the other hand sounds more lifelike, more alert and awake, refreshing, sincere, full-bodied, and most importantly to me it has a sense of presence that makes the W3000ANV sound a bit thin and shallow by comparison.
Neither one is better than the other for me per se, and both suit different moods. Most of the time however I prefer the TH900. It's just more satisfying with a wider range of music for me. I have to be in the right mood to choose the W3000ANV over the TH900, but when I am in the right mood, it's hard to beat.
As far as treble goes, I prefer the TH900 hands down, but then I tend to prefer less bright and "sparkly" top ends. The W3000ANV isn't overly bright to me, but it is brighter than the TH900 somewhat. I feel the upper registers are closer to neutral on the TH900 than W3000ANV. In both cases the treble is clear, crisp, detailed, exciting and involving. I don't think the TH900 loses out by being more restrained in this regard, but some may like the little bit of extra bite that the W3000ANV has up top perhaps.
This is sort of an oversimplification, but for me it comes down to this: I'm of the opinion that in most technical aspects and in presentation the TH900 handily bests the W3000ANV, however the W3000ANV has a very specific coloration that the TH900 (and most other headphones) do not reproduce, so if you're looking for that coloration in particular, the TH900 isn't going to replace it.
