Subject to the dollar threshold, it may make them an MSB:
(3) Issuer of traveler's checks, money orders, or stored value. An issuer of traveler's checks, money orders, or, stored value (other than a person who does not issue such checks or money orders or stored value in an amount greater than $1,000 in currency or monetary or other instruments to any person on any day in one or more transactions).
...but they are not required to register as an MSB.
(a) Registration requirement--(1) In general. Except as provided in paragraph (a)(2) of this section, relating to agents, each money services business (whether or not licensed as a money services business by any State) must register with the Department of the Treasury and, as part of that registration, maintain a list of its agents as required by 31 U.S.C. 5330 and this section. This section does not apply to the United States Postal Service, to agencies of the United States, of any State, or of any political subdivision of a State, or to a person to the extent that the person is an issuer, seller, or redeemer of stored value.
For the best discussion of stored value cards I know of, go to page 20 (document, not pdf) of the U.S. Money Laundering Threat Assessment.
For those who don't understand the risks perceived in MSBs generally, read the entire section.