As a Scots Spurs fan i think this could be a very good appointment - it could also not work at all but i don't think he's any more of a gamble than the 'proven' managers were in that he is likely to work with Levy a bit more. I don't like the way Levy works and keeps the bargain shopping list handy and pressure on him and ENIC must be continued but it must be easier having the manager at least accepting the current limitations he has rather than constantly moaning about how bad the team is - that can't help players.
There's not much i can add to what others have said about watching Celtic up here other than they just kept going, fast, pressured football. Very rarely have i seen them take the foot off even when a good few goals up. As others have said it's not necessarily about how the Old Firm keep winning that should be noted it's the way that Celtic have done it the last few years, there's been some decent signings but most of it is down to coaching (Ralston and Taylor are prime examples of how he's improved them).
I can't see him taking any players but one who might be worth a punt would be Matt O'Riley. He's been tremendous in midfield and is unlikely to cost very much.