Here's what I have found:

If you save music to your PC through Windows Media Player as regualr WMA
(not lossless, variable, or mp3) it appears no conversion is necessary.

The VCast manager that comes out of the box (at the time I bought it on
December 15th) seems to add the VCast store to Windows Media Player.  That's
it!   But on the box, there is a sticker that gives a URL to download a
separate application to rip music from a CD.  It goes through a wizard that
basically asks where you want to save the tunes on the hard drive.  (the
ripping process to .wma is probably licensed from Micro$oft).  There is
another process that runs in the background that goes through your disk(s)
and adds any and all music (.wma and .mp3) to the library.

There is no menu bar at the top that lets you manage the application as far
as application properties go.  I would say you can manage most of your
preferences from Windows Media Player.  You can also burn CDs although I
have not done it yet.

I am not excited about either product but Verizon's app can find information
about a CD that M/$'s app can not.

~alan