I like to think I already helped address the whole concern with the "are the 200 spells really actually necessary" issue. The problem with Borderlands isn't that you use only a select few guns. It's that, for a lot of the guns, the biggest differences are actually purely statistical. One gun barrel can fire at a high velocity but do low damage and lower the fire rate a bit, like you might want for a sniper rifle... but if the sight doesn't have bonus critical damage on it, then it's useless. All the pieces do are change minor little statistics. But, don't forget. You multiply all of the part combinations by fifty, because every gun can spawn at any level requirement, and the level requirement acts as a 50-level tier system that upgrades the stats little by little. All that changes are the numbers, and I don't think Gearbox would even try to deny that. Bajillions of guns is a marketing term, nothing else.
We're talking probably some thematic spells (As in, ice ball versus fire ball versus energy orb) that have little difference, or purely a status ailment kind of difference. We're also probably getting spells more akin to say the difference between the knife, cross, and axe in Castlevania. They each have their uses, and are excellent in unique situations, and end up governing your playstyle, based on what you have available.
This is something I've always loved about Metroidvania games and in part something I love about Orcs Must Die!. Why do they get so many playthroughs by me? Because, as I gain subweapons or special abilities, I'll try out different ones and see if I can't take a boss down in a different style than I did before. The only reason this works out is because the spells are legitimately different, not because the statistics are slightly different. I'm sensitive to the littlest changes in my play style, and I really like to switch it up now and again. Now, if the spells don't end up working out like that, then I'll be disappointed... but the way Chris, Keith, and co. are making it sound, each spell is going to be at least a little bit different, likened more to subweapons rather than glorified projectiles with different names, numbers, and particle effects.