ToeJam & Earl have popped up over at Xbox360Achievements under the tag of Sega Vintage Collection. That suggests that not only is Toejam and Earl imminent on XBLM, but that it's part of the next bundle of Sega classics for both XBLA and PSN.
The last Sega Vintage Collection (Numero 3) came in May, bringing old-timers like Super-Hang On, The Revenge of Shinobi, and Alex Kidd in Miracle World to 360s and PS3s. What the next collection may offer is anyone's guess - beyond ToeJam and Earl, that is.
There remains no official Sega announcement on an XBLA or PSN release of ToeJam and Earl. However, back in July the creators of the game confirmed to XBLAFans that the publisher is planning to release it on XBLM and PSN. We've reached out to Sega for confirmation.