There are several reports (RCR Wireless News, TheFeature) suggesting that Qualcomm have abandoned their EV-DV chipset development in favour of VoIP across the EV-DO Revision A standard.
Update: Sprint also commit to EV-DO with a future VoIP network and officially discarding EV-DV (see here for more information). Sprint are accelerating their plans with network trials early 2006 with the possibility of rollout late 2006. Sprint Vice President of Technology Development Oliver Valente said "voice capabilities of Rev. A make it applicable to Sprint's entire footprint".