What is the pilot's obligation to verify a registration has not expired?
You verify new (expiring) registrations the same way you verified the old (&quot;for life&quot;) registrations -- by looking at the document. You just have to pay attention now (it's not just &quot;It's there&quot;, you need to check the expiration date too).
New-style registration certificates (issued some time after October 2010) are supposed to have the expiration date clearly printed on the certificate (In the lower-left corner, under the date of issue).
For certificates without an expiration date printed on them (registered prior to October 2010) the FAA established a table of expiration dates back when the re-registration requirement was initiated.
ALL of the old certificates have expired by now: The last ones expired December 31, 2013.

As regards the pilot's liability, an unregistered aircraft (or one with an expired airworthiness certificate) is de facto unairworthy:

Does expiration of registration affect an aircraft's airworthiness certificate?
Because an aircraft with an expired registration is not registered, its airworthiness certification would be considered ineffective. Without registration the aircraft is not authorized for flight.
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From The FAA's registration FAQ.
Aside from being a violation of the FARs to fly the aircraft with an expired registration (because it's &quot;not airworthy&quot;) this triggers other implications, for example most aircraft insurance is invalid if the aircraft is &quot;not airworthy&quot; .