Um, no, the USPS is running in the red. They said themselves that they were $10.5 billion in the red for 2011. After correcting for the $5 billion pension payment, they are still more than five billion in the hole.
USPS are insolvent, regardless of the pension payments.
The Postal Reorganization Act requires the Postal Rate Commission to consider only lawful postal costs in its determination of what postage rates may be and they didn't allow USPS To claim that cost.
They've been paying the $5 billion since FY 2007 ~ and it has been exceedingly destructive of sound financial management.
At the same time, as you saw in the Senate vote, Congress will not allow USPS to shed unnecessary operating costs.
It may well be time to start burning down useless post offices ~ since the law does allow USPS to not reopen a post office that burns down.
Regarding insolvency, they continue to be a government agency ~ and even if 'Bailed Out' they'd still run a smaller deficit than Commerce, State, Defense, Energy, Education, Human Resources, .........