Henson is given the inside centre berth and forms a midfield partnership with Jamie Roberts (Blues), who makes the positional switch to take up the outside centre spot vacated by Davies.
Up front Dragons duo, hooker Lloyd Burns and second row Luke Charteris, are given the chance to pick up where they left off last weekend, impressing after coming on from the bench, with Burns making his first start in a Wales shirt.
Elsewhere Warren Gatland and his coaching staff have said 'same again' to the side who outscored England by three tries to two at Twickenham. Both props, Paul James (Ospreys) and Craig Mitchell (Exeter Chiefs), are retained as is lock Alun Wyn Jones who forms a new partnership with Charteris.
The now established back row unit of captain Sam Warburton (Blues) and Dragons duo Dan Lydiate and Toby Faletau also continues. And the 'makeshift' half-back pairing of Rhys Priestland (Scarlets) and Mike Phillips (Bayonne) which was thrust upon Wales after a last minute injury to Scarlets fly half Stephen Jones during the warm-up last week, has also impressed enough to be handed a second outing.
Shane Williams (Ospreys) and George North (Scarlets) both keep their places on the wings.
On the bench there is no room for the displaced Scarlets centre Davies this week or for Blues lock Bradley Davies, who made way for Charteris.
Ryan Jones is also missing after picking up a calf problem which means Scarlets back row Josh Turnbull and uncapped Ospreys flanker Justin Tipuric could both be handed chances to stake a claim for RWC selection.
Huw Bennett provides the front row cover in a straight swap with starter Burns, alongside fellow Osprey, Ryan Bevington (prop).
Scarlets pair Tavis Knoyle (scrum-half) and Scott Williams (centre) are also retained to provide cover for the backs with Dragons wing Aled Brew joining them in place of Blues scrum-half (and the travelling 23rd man at Twickenham last week) Lloyd Williams.
"We need the win this weekend - it's as simple as that," said head coach Gatland. "We've told the players that, for us to be regarded as contenders at the Rugby World Cup we need to beat England at home this weekend, to send out that message to everyone that we are contenders.
"We have the toughest Pool at the tournament and in less than a month's time we will be facing South Africa in our opening match. It is vitally important that we go into that match with the sound of Welsh fans ringing in our ears, fans who have cheered us on to victories in the final two matches of our warm-up campaign against England and against Argentina next week.
"We have retained the majority of the side who travelled to London last week and told them that we want more of the same. There are one or two players we have brought in to have a look at but the reason we have deliberately not made wholesale changes is that we need to win this game and we believe these are the players who can do that."
Assistant coach Rob Howley, added: "This selection has been about consistency and about putting in a performance on Saturday which will enable us to build to the World Cup. Rhys is retained after impressing under difficult circumstances last week, James comes in at full-back and we all know what quality he has to offer in a Wales shirt and Gavin gets his chance.
"We were impressed with both Lloyd and Luke coming off the bench last week, Lloyd particularly deserves an opportunity to make his first start for his country and Luke will form a new partnership with Alun Wyn Jones which we think can go well. We have also brought Josh Turnbull and Justin Tipuric on to the bench, two young players who have impressed us in training and who will be hungry to make their World Cup claims and Aled Brew will give us physicality and pace out wide if required."
WALES: James Hook; George North, Jamie Roberts, Gavin Henson, Shane Williams; Rhys Priestland, Mike Phillips; Paul James, Lloyd Burns, Craig Mitchell, Luke Charteris, Alun Wyn Jones, Dan Lydiate, Sam Warburton (Captain), Toby Faletau.
Replacements: Huw Bennett, Ryan Bevington, Josh Turnbull, Justin Tipuric, Tavis Knoyle, Scott Williams, Aled Brew