It wouldn't surprise me in the slightest if the Tories got in..... Someone mentioned party organisations earlier, and I do feel that this has a disproportionate effect in marginal seats. The Tories concentration and funding on these seats in 2010 was pretty crucial.
Interestingly, it seems that Conservative Central Office have included Hazel Grove in a list of 40 target seats to win in the forthcoming general election. See
http://www.conservativehome.com/parliament/2013/05/by-mark-wallacefollowmarkon-twitter-in-october-cchq-announced-that-it-was-launching-a-4040-strategy-aimed-at-winning-the.htmlWith a Lib Dem majority of over 6,000 at the 2010 election, that can't be because it's regarded as marginal, so it must presumably be because they think they are in with a chance because of Sir Andrew's retirement.
So no doubt we can expect a much more visible Tory campaign, with bus loads of canvassers coming here, and lots of money thrown at leafleting and postering etc.
6,000 is a sizeable majority to overturn, so on the face of it it seems unlikely, but stranger things have happened! And Mr Wragg, unlike Ms Smart, is a genuinely local candidate; that will no doubt count for something with some voters.