Um...that would work, but your full of shit

Good question.  And why did she say she would only after she was nominated?:

Hillary Clinton claims she's battle-tested, but she won't let the public test her tax returns. While Barack Obama has released his into the clutches of the forensic accounting crowd, she's steadfastly refused to make hers available. The only financial disclosure she's made is the obligatory filing that is similar to what members of Congress have to produce, but which has far less detail than the actual tax returns would provide.

In fact, the disclosure documents are essentially a shield, revealing only "income sources and investment holdings in broad financial categories" notes ABC News. They disclose "...only a fraction of the information available on tax returns."

Truth is, she's following in the footsteps of her joint-filing spouse. According to ABC, "Since 1984, only one major presidential candidate -- Bill Clinton in 1992 -- has refused to release the tax forms he sent to the Internal Revenue Service."

[...]

The question at hand is why Senator Clinton is allowing this to remain a political issue, and encouraging us to savor the hidden treasures -- questionable sources of income, wily tax moves, inappropriate pantsuit deductions -- rather than swiftly removing it from the table by taking those suckers out of the vault?

Does her refusal entitle us to think the worse? I believe it does, given that her campaign is masterful at calculation, that it must have done the strategic arithmetic and decided that the heat they're taking for non-disclosure is less hellish than the alternative. After all, as ABC pointed out, "Only tax forms would reveal whether a wealthy candidate -- many of the 2008 candidates are multimillionaires -- have used loopholes to duck taxes."

Senator Clinton's position is symptomatic of a deeply troubling, imbricated pattern of her campaign: selectively playing-by-the-rules, while universally claiming the high ground as both moral leader and political victim.

Adam Hanft - Why Won't Hillary Clinton Release Her Tax Returns? Huffington Post 13 Feb 08

How much effort is it to link her to her husband, for pity's sake.  I thought this was meant to be the 'two for one' co-presidency.

I think it's obvious, they are very smart people and they wouldn't hide something unless they knew it would damage the campaign or else they would do it to prove our transparent they are.

This is a clue everyone!!  Wake up.  they are hiding many things they don't want us to know.

Just think about what they will hide from us in the Whitehouse.

The person above who talked about the disparity between Obama and the Clinton's incomes is on the right track.

Also, remember the WSJ article that talked about Bill supposedly winding up his relationship with Ron Burkle's fund. It may be that this has already happened and that they've made $20,000,000+ as has been reported. Not only will this create an opening for the media and the GOP to go back into the Clinton's finances, not to mention the source of these funds (Dubai etc), but it will be kind of tough going into blue collar type town with news of a $20,000,000 windfall all over the front page.