Australia still favourite despite McGrath rumours
England have drifted again, moving out to 11/4 (3.75) while the draw, which the bookies have taken plenty of money on in recent days, remains a 7/4 (2.75) shot and one that would leave the series perfectly balanced going into the final Test at the Oval.
As it was after Edgbaston, the closeness of events at Old Trafford makes it incredibly hard to know how both sides will respond. Will Australia carry over the momentum of escaping from the jaws of defeat? Or will England, roared on by the home crowd, assert their dominance again and take the lead with just the Oval Test to go? And then there's the weather. If we get a day of rain, suddenly the draw is a real option.
Should McGrath be fit, that could spell bad news for England as he has managed 12 wickets in his previous two matches at Trent Bridge. Shane Warne's record there is even better, with 21 wickets in three Ashes Tests.
Australia's record there is nothing amazing - seven wins in 20 matches - but they've lost just three times and they won the last time the two sides met, in 2001. England, on the other hand, have only won 15 times in 50 Tests at Trent Bridge, while they've lost 14 times and the rest have been drawn.
Shaun Tait will replace the out-of-form Jason Gillespie, but the important news will surround McGrath, so keep checking back for all the latest betting news.
Please note that odds are correct at time of publication and are subject to change.
Simon Cambers is Cricinfo's new betting correspondent