Depending on what you want out of sorcerers, it could go a few different ways.
If the idea is that wizards prepare magic while sorcerers have it in-born, you could have a wizard that uses his spellbook magic once per day (selecting from a few spells he prepared in his adventuring spellbook), while a sorcerer would know fewer overall spells, but always have them at the ready. This won't be a dramatic mechanical difference -- essentially the difference between a longsword and a monk's fist -- but it would feel a lot different.
If the idea is that wizards carefully ration their magic, while sorcerers have it oozing outta their pores, you could give sorcerers something like "at-will" magic, and leave the one big spell per day to wizards. This way, sorcerers are always (or frequently) blasting around magic, while the wizard has to carefully ration his one spell per day. This would require developing slightly different spells for sorcerers and wizards, and that wouldn't be a problem for me, at least.
Personally, I'm fond of the idea of giving sorcerers different spells: more transmutations, more evocations, more "flashy magic," perhaps tied to a draconic bloodline (my blue dragon blood lets me use all sorts of illusion-deserty-electric jazz! your red dragon blood lets you do all sorts of divination-fiery-strength jazz!), but that's because I think sorcs and wizards need a bit more distinction than they were given in 3e. If you do that, you can have them come back at a different rate and have a different power-level. Maybe sorcerers can do three spells per day, but each sorc spell is about 1/3rd a wizard spell. I'd be cool with that.
I could possibly get on board with that. I could see bloodlines functioning in a manner similar to clerical domains. I felt as though the manner in which 4E pacts worked for warlocks would have been pretty well suited to sorcerers.