Nail said:
Really really. It's like Darklone said, and then some:
The skill list stinks compared to the wizard, and since the wizard needs int, anyway, he gets a lot of skill points. Wizards are usually good wells of knowledge, but the Sorcerer doesn't have the class skills, or the skill points, to work that way.
Also, he just doesn't get any bonus feats (something that should have been fixed in 3.5).
He might get his spells spontaneously, but the number of spells he has is limited, so, unlike a wizard, he couldn't really prepare for a big fight, because he simply lacks the ability to change his spell make up (and expendable magic items aren't always a viable solution)
Metamagic, while being spontaneous, extends the casting time, barring sorcerers from using quicken spell (or rods of quicken spell) as a side effect (so when the high-level wizard will unload a meteor swarm followed by horrid wilting, the sorcerer can only do on).
The extra spell slots aren't that big a deal since, as has been mentioned, they lag behind one level with new spell levels.
Of course, some of these things were addressed in extra books (something that should not be necessary IMO), like the option where you don't get a familiar but can use metamagic without extra casting time, or many house rules, but that's neither here nor there.
As far as I know, the sorcerer was brought into 3e late, shortly before the release: You see, they were testing the spontaneous way of spellcasting as the new thing (clerics, getting access to their whole spell lists, were real scary), but that didn't work out, so the wizard, druid, and cleric got the old rules (although the cleric, and later the druid, was given the option to convert some spells). But they didn't want to abandon the new concept, so they let the bard keep it, and introduced a new class which was basically a wizard variant: The sorcerer. Same spells as a wizard, but new concept, different casting attribute, smaller spell list.
What the sorcerer needs:
Some class features, even if it was only bonus feats (maybe sudden metamagic, or those heritage feats)
Earlier access to spell level (that one level lag serves no purpose obvious to me)
Maybe a better HD, as well as more skill points (and a larger class skill list)
But personally, I don't bother with trying to fix the sorcerer, any more, since there are now 4 classes that fill the gap (warlock, warmage, dread necromancer, beguiler, not to mention psionic characters). But they might come up with a real sorcerer class (instead of a disguised wizard variant) in 4e with some distinguishing features. Something which I would applaud.