It's going to be an emotional game in Glasgow, that's for sure. Scotland can afford to be quite happy with their position, but I suspect that a good many of their fans would trade for Ireland's if they could, being on 7 points, a hearty goal difference (courtesy of a team who really shouldn't be in the competition IMO), no lost games and two very good away results. That's why I think we'll see the lion's share of the attacking play from the Scottish in Glasgow, especially in the 1st half. M'ON will probably be setting his team up conservatively once again to soak pressure, to frustrate, but also with a more adventurous player like Hoolahan in midfield and a slightly more expansive formation to give Ireland a proper counter attacking threat, as he won't give Scotland quite as much creedence as a team who can get in behind Ireland's lines like Germany could.
It's been nearly 20 years since Ireland have played another of the nations from 'these islands', that wasn't Wales, in a proper competitive derby (sorry, Carling cup). Some atmosphere will be experienced, some craic will be had. Looking forward to it.