As far as I see it, Market Makers help to stabilize the exchange rate, Market Takers destabilize it. Surely, it's in mtgox's interests for the price to stabilize so that more people can adopt bitcoin and increase their customers.
The solution to this seems to me to be quite simple, and is something Intersango already implemented a while back. Simpy: reward market makers, and penalise market takers. IMHO, all exchanges would be wise to do this.
I'd actually like to see no more than 0% commission for market makers - perhaps even a negative commission considering the importance of their role. Funding from this would naturally come from the transactions made by the market takers.
I don't claim to be an expert on economics, so apologies if I'm completely missing something here. (If I am, Intersango was too, though!).
If enough people are interested in seeing this happen, and comment, perhaps mtgox will address this.
Bitfloor, closed down as of last night did this very thing: -0.1% (negative fee) for makers, 0.3% (positive fee) for takers. It did seem to improve stability a little, but also (this could have been caused by other factors) resulted in higher prices.