Thomas will bolster the backs, while the Blues made it a double deal on Saturday by announcing the signing of Taranaki and Hurricanes lock Paul Tito.

"It's a done deal, we've signed Gareth and New Zealander Paul Tito," Blues chairman Peter Thomas told BBC Sport.

"Gareth's prowess speaks for itself, while Taranaki captain Tito follows the path of Xavier Rush and Ben Blair."

Tito, 28, is out of contract at the end of the 2007 Super 14 and will bolster the squad during the World Cup and beyond, with the Blues likely to lose Rob Sidoli, and boasting that they may also lose young Bradley Davies to the Wales squad.

"The New Zealanders in our squad have added a real edge," Thomas told BBC Radio Wales' Back Page programme.

"We're targeting the best players and there should be two or three more quality signings to follow Gareth and Paul before next season."

But it is Thomas who will be the centre of attention, coming home to Cardiff where he spent five years before heading first to the doomed Celtic Warriors and then to France

It is believed he may retire from international rugby after the World Cup - in which, should he play all the Wales Six Nations games and enough warm-up matches, he may win his 100th cap.

However, his international retirement is not a part of the deal, as it was for Mark Taylor at Sale Sharks for example.

"It's not part of the deal that Gareth retires from Wales, but what he does after the World Cup is up to him," said the Blues boss.

"We'll be giving him 100 per cent support during the World Cup and we're delighted that he's coming back to us."