But you're basing that on his performances in 2007 and 2008 Gingergenius. Back then, Hook was a good player full stop. Most of Wales were crying out for him to be the permanent starter at 10 instead of Jones in '07. In '08 him and Jones were given equal gametime, which really helped Wales win the grand slam, as they could bring on someone who would completely change the playing style.
Hook hasn't become a terrible player overnight, he has however been exposed at fly-half, where his game managment isn't up to scratch. He remains a good running player with good distribution and kicking game. From that description, he seems perfect for centre (especially now his defense is solid). He could combine well with Roberts (who's no slouch MunsterMachine, hence him playing on the wing in his first cap), as they are very different players. The problem I see with the previous combinations with Roberts involved are that they are too similar. Robert - Shanklin, Roberts - Davies, even trying Roberts - Bishop is similar. If I were Gatland, I'd try a Hook - Roberts combo and use a game plan where the two constantly switch positions depending on quality of ball and whats in front of them.
Hook has the ability to beat defenders with his footwork (so if there's some forwards in midfield, he should be at 12), whilst Roberts can run through tackles (if a winger is filling a gap in midfield for example). With Lee Byrne back and looking good, he will increase the attacking options in midfield, and hopefully allow Roberts a little more space. Bring Shane and the other winger in to run supporting lines alongside Hook, Roberts and Byrne, should be dangerous.
We need to also consider a midfield without Roberts. He's showed he can be a great player, but if we can't get a combination that works, we need to find one that does. This is still why everyone goes on about Henson. He really is Wales' ideal centre. He has great distribution (the best in Wales), can break the line (although lacks a bit of pace), has an awesome kicking game (when he didn't have a groin injury, i.e. pre 2006), can take the ball up as well as most crash ball centres, and offloads well out the tackle. At least we have an oportunity to develop some new centres while he's out. Roberts would haver have switched positions if Henson was still playing for example.