I also get the impression it's 100% done. No way would Arsene be making declarations like that if it wasn't (speculation about his future on Ars.com a day before kick off, seriously).
Replace from within? we have much freedom to decide? he listed:
Diaby, Caz, Ox, Wilshere, Ramsey, Arteta ("and frimp returns too"). Allow me to put Frimmerz on the side for a sec. There's Diaby as a physical presence, and all the rest will return to the shire after destroying the ring. And Diaby is not exactly reliable - both injury and playing that role.
It's all good to have the ball and score more, but we've learned (courtesy of fat Sam, Stoke and other great personalities) that we can't allow that teams will bully us of the field. And we have to have someone apart from Art that can play from deep naturally (I'll be happy with Sahin, in other words). There has to be a proper replacement.