Credit to StanBowles22 of TA
A status update on facebook has revealed that Pinball Hall of Fame: Gottlieb Collection will be hitting XBLA in January 2011.

From the status update, it is looking like this will be a standalone release, rather than DLC for Pinball Hall of Fame.

GREAT NEWS PINBALL FANS....Pinball Hall of Fame: Gottlieb Collection is coming to XBLA January 2011. This is the first time Gottlieb Pinball will be available to the Xbox 360 community. The HD graphics are amazing and it will include all the same tables as the previous Wii version. More info to come.
The tables included in the Wii version are:-

• Ace High (1957)
• Big Shot (1974)
• Black Hole (1981)
• Central Park (1966)
• Genie (1979)
• Tee'd Off (1993)
• Victory (1987)
• Play-Boy (1932)
• Xolten
• Love Meter
• El Dorado City of Gold (1984)
• Goin' Nuts (1983)
• Strikes n' Spares (1995)

No announcement has been made at this time regarding price or a firm release date.