I don't know who answered you at Henson, i think they tend to give 'fan friendly' answers, but it's pretty unilkely from a TV point of view they'll be able to use Clifford as an active character without having someone else voice him or paying out quite a bit for Kevin Clash to come in freelance and do one character on the same money the other guys get doing a whole bunch of them - unless i guess they decide to just have him in the backgrounds not speaking like they do with others.
I don't like the character much, never thought he was right for the Muppets, certainly wasn't anywhere near strong enough to host a show and i don't feel he works well with the classic Muppets like Pepe and Dr Phil do - still not convinced about Johnny Fiama yet either. To me Clifford is the Muppet's version of Sesame's Elmo although i'm talking specifically about the character, not the action figure which will be great !