This is the first time I've seen this thread over here.
Check out the Wizards of the Coast message boards. They have had something like 100 threads on this very topic, and they never tire of rehashing the same arguments over and over. At no stage has anybody there ever said "Wow, I hadn't thought of that. I've changed my mind."
Personally I love sorcerers. They are great fun to play. I couldn't care less whether or not they are "weaker" than wizards. As soon the 3rd edition sorcerer came out I realised I was never going to play a wizard again.
However, to answer your question, my OPINION is :-
Given a reasonably experienced player who is willing to spend a considerable amount of time planning his character
Given a DM who is not looking to mess over his players, but believes in challenging them and occasionally targetting their weaknesses (so the sorcerer may sometimes be stumped because he lacks a spell, the wizard has to spend resources protecting his spellbook, and can't always take the time to scribe scrolls, come back tomorrow with the optimum spells prepared etc.)
Given fairly random treasure hauls which doesn't favour any particular character class, but with all characters having to "pay" for magic items they keep (rather than as sometimes happens, useful items being given to those who best suit them, and only the proceeds from the sale of any remaining items being split equally)
Then a wizard is slightly stronger as I think greater flexibility and gaining spell levels earlier gives him the edge.
What does annoy me though is people who think there's only one way to play D&D - hence my listing the assumptions behind my opinion.
In particular, wizard lovers quite often assume that any BBEG spellbooks they come across are theirs by right, but they should also get a full share of the remaining treasure. You can play that way (our group does), but my opinion is that the "default" way to play is to split treasure equally and that is the only fair basis on which to compare classes.
I've also heard opinions like "the spellbook isn't a weakness, because no DM would dare destroy it" but later on they say "and the sorcerer is always finding himself in positions where he doesn't have
any spells on his list that he can use to solve the problem." That to me is biased DMing and not a fair basis for comparison.