And on that note, I'll get to writing that IC post!

But just a comment on Arab Romanization. While the Arabs did indeed 'inherit' the intellectual legacy of the Romans and Greeks, they very quickly developed a culture of their own, and rather than Romanizing themselves, it was those they conquered who became Arabized - one need only look at the Arab world today to see that. I think Islam and the position of the Arabic language in it ensured that Arabic - and through it Arab culture - did not simply give way. 
Conquered people Arabizing was also largely due to the fact that the Arabs actually treated their subjects much better than the Byzantines or Persians ever did, and the taxes they levied (even with non-Muslims paying the Jizya) were less strenuous than those of the Byzantines and Persians, meaning that many people embraced both Islam and Arabic and became Arabized within a generation or two. It's rather shocking just how fast the Muslims managed to assimilate the lands they conquered, and with that they managed to very quickly gain Muslim administrators and bureaucrats, helping the Rashidun build some rather efficient bureaucratic systems in the various regions they had under their control.
Kinda like of a more advanced version of how Romans managed to quickly assimilate those they conquered with promises of citizenship and whatnot, thus vastly increasing their manpower to those famed reserves.

Of course, it would be interesting to see Arabs Romanize, as unlikely as that would be.