While spell-crafting hasn't been confirmed out, I'd rather have it than Dragon shouts, dragons, or any other crafting/creating mechanic. If I could only have one that is.
Edit: Apparantly a new IGN preview has confirmed no spell making? Is this true? If so, I probably wont even get Skyrim.
I might put off getting it until a DLC or mod gives us spellcrafting if it is out. Honestly it is that important.
As for the "new" system can anyone actually say how it adds anything to the game. It is a serious question. So lets say, pressing the left mouse button throws a fireball, holding it down creates a flamethrower, left [censored] and left mouse is setting a trap, and block+left click is a point blank area of effect. Oh wow, look how zippy that is, it adds so much. But wait, I press hotkey 1 and throw a fireballs, hot key 2 and it is a flamethrower, hot key 3 to set traps, hot key for to point blank area of effect. So basically I got a expanded hotkey system. I'd rather have 1-0 and shift 1-0 and cntrl 1-0 for specific spells than the new system.
Losing spell crafting for a expanded hotkey system just isn't worth it. We are giving up thousands of spells(technically more but practically thousands) so we can get a few hundred spells with a slightly superior interface. I guess xbox people get a much better interface since hotkeys were hugely limited, but I'd rather pause and pick a spell from my custom made spells than have like triple the spells mapped to my x,y keys.