I've just found this article on this french site:
http://www.jeuxvideo.fr/wipeout-hd-i...tu-129104.html

Well, nothing really new here:
Developpement of the game has started in springs 2007, with a team of 6 persons, then has grown until 30 people. According to Colin, there is a great team spirit, as they're all great fans of the franchise.
They have also worked hard on the online part, and the graphics (we've already noted that ), there will be for sure downloadable content.
The only new info here is that the Sixaxis control "should only be used in some cases, such as weapon use".
It's also said that the game is being finalized and given the fact that it won't be released in Blu-Ray, it should arrive on the psn soon...