Well I don't see him ousting Xavi or Iniesta for that matter from that lineup. Not denying that he is talented, but will he get his chance there? He might do, he might not but at this moment in time surely you'll agree in saying Wilshere is the better player. Purely for the reasons stated above, he's not just potential anymore, he's delivering on it.
Difference of course being, that Xavi & Iniesta are one of the best if not THE best midfielders in the world at the moment. Ousting such solid starters that have been the backbone of our team for a good while doesn't come easy.
To be fair, I fancy Thiago will get plenty of chances this season and will most likely be blooded into the first team. The kid's an exceptional talent and playing in "La Liga Adelante" won't hurt him either. He's been performing for both the U-19 and U-21 teams on quite a constant basis and it seems he just might be the one taking over from Xavi.
I'd have to say, after a careful assesment, that Wilshere is truly better at the moment for the following reasons. The circumstances have been substantially different in Arsenal if comparing to Barça. Your midfield's not as good as ours at the moment, which we clearly saw last spring and you've had your fair share of injuries coming in, leaving Wenger no option but to play such an exciting lad as Wilshere. It would be interesting to see how Thiago would fair in similar circumstances.
However, I'm not taking away the fact that when called upon, young Jack has definitely filled the void and taken upon all the responsibility in the world. He does have a manner of recklessness around him, but it's merely inexperience and he'll get past it. So I have to admit, you might be right.
Shit, this is why i would wish you guys to keep Cesc and us blood in kids like the Alcantara brothers, Riverola etc.
To add one more thing - Thiago is actually the better player when looking at the mere overall attributes of vision, passing, dribbling, footballing brain, but unfortunately Wilshere indeed plays at a higher level, which makes him actually prove himself, thus getting better each game he plays.