I think it's probably easier to imagine what won't change or only obviously:
1) The Franks will be the major power of Western Europe. Elimination of the Visigoths and the ransacking of Aquitaine certainly helped, but they'll still control the richest part of France even in this TL.
This means, IMO, that Bavaria/Saxony/England/Lombardia will inevitably remain on similar trajectories; Christian/Catholic regions. The question is if they will actually be united as historical - I can certainly see massively different realms, but the weight of Frankish influence will keep much the same.
Likewise, Spain will probably be Christian/Catholic. It might fall apart, it might remain a united realm, but Frankish Catholicism is a likely thing.
I suspect, even, that very soon after the POD the Franks will come to temporarily rule much of their neighbourhood, but it's tricky where and what; Lombardia seems likely, as the Pope will want them there, but picking between Saxony (poor, but close to the ancient Frankish lands) and Spain (richer, but across the half-independent Aquitainian/Occitanian lands) will be harder. Eventually, it'll all shatter again anyway.
2) Byzantium will dominate the Russians. The Black Sea won't move, and I hardly think Byzantium will lose Anatolia or Constantinople, so whatever invaders or locals live west of the great Steppes will be Orthodox, most likely. The Norse aren't strong enough to win, and the Catholics (if they're even different enough to inspire conflict) need the long way round to get to Russia.
I also expect this will have an effect on the nearby Steppe, so most lands west of the Ural will eventually become Christian in the Greek-Russian style.
3) Whoever controls trade between Asia and Europe will tax it up the wazoo. So if/when naval capabilities allow it, someone will try a route around Africa, and probably find America (if noone does it sooner).