I think the problem here is not between Hughes and Robinho, even if they're best friends, it doesn't mean that Robinho would stop wanting to go to Barca.
Many sources are saying that it's his personal wish (and a pretty strong one), and even if we accept that it's a paper talk and it could be rubbish or not, we could not miss an argument or two. And the strongest one is that after all, Robinho is a brazilian and for every south american Spain and spanish football would fit better than England. Not just in terms of playing style, but it's also about lifestyle - climate, weather, culture and things like that. And in this case he's not wanted by just "some spanish team", he's wanted by the champions of Europe, the most attractive and entertaining team in the world atm. Tempting, huh?
So, what I wanted to say .. even if Robinho didn't say personally "I want to go to Barca", we could easily find one or two reasons why he'd want. And of course, not at last - don't forget the huge difference between Barca and City. In everything. Sorry bluedick, you know I'm speaking the truth.
And as about City's attitude about that, my personal feeling is that they'd never want to sell him, if we were talking about January 2009. Robinho was the first huge purchase of City and an year ago he was a true luxury at Eastlands. A player of which calibre this ground has not seen from much time ago, so it's easy to say that he was untouchable there. But now, after they bought Adebayor, Tevez, Roque and God knows who else will come, I think Robinho is not that flashy diamond anymore. He's not the guy everybody there is talking about, he's just in one team with Adebayor and Tevez. One of them, but not The One. So, it's not too hard to think that he's actually replaceable already. You sell Robinho, you buy Ribery. You sell this, you buy that. What's the difference for you ?
Remember that if someone hands a transfer request, desperately wanting to go somewhere, the history barely remembers a case when it's not being granted. It's the best solution for both sides.