No, but there is a shuttle bus to Busch Gardens Tampa that leaves from the bus stop near CityWalk. (It's under the bridge that runs from CityWalk to the parking garages.)
It has a single departure at 8:15 a.m. and last time I checked it cost $5 per person unless you have a 5-day FlexTicket, in which case it's free.
Lynx, Orlando's bus company, has service between Universal & Disney. Routes 301, 302, and 303 have stops at the intersection of Vineland Rd and Kirkland Rd. Visit www.golynx.com for more information and route maps.
Of course, you can always ask the HRH concierge to summon up a taxi. I believe the fare to Disney is in the $30 to $40 range.