Looks like Sprint's Power Vision site is a go, and damn if they aren't extremely competitive with Verizon's own EV-DO service. So competitive, in fact, Sprint apparently managed to undercut Verizon by multiples of price with their EV-DO services. So here's whatcha got:
Their Power Vision Access Pack, the lowest-end service, includes all you-can-eat unlimited EV-DO for $15 a month (and includes streaming news and music)
The Power Vision Plus Pack goes for $20 a month, and includes unlimited imaging (i.e. MMS), and Sprint TV Plus (streaming content from ABC News, Fuel, Fuse, Fox News/Sports, etc.)
The Power Vision Ultimate Pack is $25 a month, and includes all of the above plus yet more channels (including NBC, ESPN, Discover, TLC, etc.).
So basically with Sprint you pay a maximum of $25 per month on their Pocket PC phone (the PPC-6700) to Verizon's $45 on theirs (the i730). However, when you compare stripped-down EV-DO with multimedia-centric services on a non-smartphone (like Sprint's MM-9000 or A940 vs. Verizon's A970 or Moto E815), it looks like V CAST has the advantage over Power Vision by between $5 to $10 per month. Unfortunately details on their music download service (Sprint Music Store be the name) is still a little oblique, so we'll have to ring you back on that.