Hardhead
Explorer
The problem in 2nd Edition was that TSR kept introducing new options which were not just different, but BETTER. Serious power creep, often in the form of kits. WotC prestige classes have been better (although everyone can probably point to one or two that are unbalanced).
Two words: Mystic Theurge.
Andy Colins even admits to "pushing the envelope" with it. The problem is, you shouldn't be pusing the envelope in the core rules. You should be setting the base line. Like it or not, power creep is here. Power levels are being ratcheted up in the core rules, and they'll be ratcheted up further in the next few years.
According to the dictionary, when you "push the envelope," you increase the operating capabilites of a technological system. In other words, you set a new high-end benchmark. However, in a game system like 3e, if you assume the system is balanced before, when people constanly push the envelope, you end up with power creep - arguably *massive* power creep in the case of the Mystic Theurge.
Each time someone pushes the envelope, the next person to do so will push it further.
I was really hoping 3.5 would take the opportunity to sort of "reset" the power creep and demonstrate what should be considered a baseline for PrCs, feats, ect. Instead, if what I've seen is any indication, they've simply upped the ante on power creep.