You know...I'm not so sure Guardiola would necessarily be as good an appointment as it might appear on the surface.
Sure, he oversaw arguably the greatest team ever, but there's a few key points to consider.
Firstly, he's only ever worked with one club, who's star players already have the style and philosophy he wanted to implement running through their blood since childhood. It's far harder to teach a set of players to play tika-taka if they're in their 20s and 30s. Secondly, he inherited a phenomenal team at Barca. Sure, he made changes and got them to perform, but I think he'd be in for a big shock if he tried to play similar tactics but with Defoe, Huddlestone and Lennon as he did with Messi, Xavi and Iniesta. He'd command huge respect in the dressing room, but it remains to be seen what he can do when outside his comfort zone.
Thirdly, his record in the transfer market is patchy at best. Sanchez, Villa, Fabregas, Alves, Mascherano etc are all very good players but they were very high profile when he signed them for huge amounts of money. His four seasons there saw him also waste huge amounts of money on the likes of Ibrahimovic, Hleb and Keirrison. Now you can argue that in the continental style he doesn't have autonomy over the transfers and has to make glamour signings to appease the fans, but still, he is largely unproven in this area of management, especially as all of his best players came through the Barca youth team. And if he looked to the Spurs youth team hoping to find another Pedro/Busquets, he'd have another thing coming based on the last 10-15 years.