Well, V4 has been provided to betatesters, and they have started to release recordings of their testing.
With regards to the question; I havent seen any pre-order options for V4 (I havent looked very hard tho).
BigD have a point that putting money up front before a product is released can be risky, so its a fair comment.
That said; the Vampire/Apollo team has delivered on the V2 front, so I wouldnt feel it to be a risky venture to pre-order V4 if that option was available.
I understand the intrest in such an option tho, since the V2 queue was/is quite long, and unless you ordered as soon as it was available, you where in for several months of wait.