From her letter to the Chief Administrative Officer:
I am directing that the Chief Administrative Officer’s office begin to publish the quarterly Statement of Disbursements for the House of Representatives in an online format at the earliest date. The House is making every effort to operate in a transparent manner and online publication of these reports will expand accountability to taxpayers and the press.
Though one can't be sure, this move probably had something to do with the recent scandal in the UK over expense account abuse that eventually took down several government officials including the Speaker of the House of Commons.
Regardless of the motivation, our thanks to Speaker Pelosi. With the Senate moving towards more accountability reason this is another reason to be hopeful for the future of transparency in Congress.
(Thanks Sunlight Foundation)