The 4dtv receivers can't pick up DVB, you'll need a separate receiver for those channels. You will be able to pick up some NTSC channels that are FTA, and if the 4dtv has been authorized you can pick up a few DC II channels. I'm not sure if it has to currently be authorized or not on the free DC II channels.
The 4DTV receivers need to be authorized by some service provider before they will do much of anything. That's usually a freebe. There are still a lot of analog C-band signals out there, although most of the Ku stuff is digital (MPEG, Digicipher, etc.), but there are notable exceptions.
I've noticed that some of the (what I understood to be subscription) 4DTV services come and go (a lot like analog stuff does/used to), but there is a lot of it that is free. I suppose someone mistypes an authorization code once in awhile.
As some others have mentioned, you will need an MPEG receiver, and a couple of 1gHz splitters, an DiSEqC switch, (and maybe some sort of relay switching to allow the MPEG receiver to control the polarizer), to receive those signals. Low-end MPEG receivers aren't all that expensive either.
I hope this is helpful.
(This is the edit) Oh boy. Now I'm confused. I was just looking at Skyvision and read this:
"Digital DigiCipher® II Programming. The 4DTV receiver comes with full MPEG-2 decompression capability built-in, which enables you to receive more programming per satellite in both scrambled, and "in the clear" digital formats."
Sounds like Motorolaganda, but then, what do I know.