I read somewhere that SoulxMaka is the most obvious pairing since InuyashaxKagome.. xDD
Honestly, I really don't mind either. I adore both characters as partners, and their interaction is really sweet.
There's actually plenty of great SoulxMaka in the manga too. I can't wait to see it animated. The good thing about this series is that romance really doesn't own the screen, and the same can be said of particular characters as well. All characters get their own amount of screen time. I'd say the mangaka is very good at balancing everything, and this leaves me hopeful that we won't get any unnecessary interaction.
Obviously I don't think Soul and Maka are in love with eachother, but I do think there is certain emphasis on particular things that allow us to see the deeper feelings they have for eachother. Which can obviously change later.