I'm surprised at the responses. We have been exposed in midfield ever since 2005, because of a lack of discipline and quality ahead of the defence. Only Arteta in those 9 years has done a good job at covering the defensive zone of the midfield. Clearly you all think Khedira and Ramsey suffices, even though both players are NOT of the disciplined kind. So I can't really say much more against that.
For what it's worth, we one hunnit need Khedira, but I think he will definitely form a better midfield partnership with Arteta/Schneiderlin.