I believe the W212 will come with the carry-over 3.5, 5.5, and 6.3 liter engines, as well as the same V6 bluetec diesel. There is a hybrid in the works. Also, MB released a teaser hinting STRONGLY (If they release a concept car, it means probably yes) that the E250 with a 2.2 litre 4-banger bluetec diesel will make it stateside. This engine may also make it into the W204 and the GLK.
And I wouldn't get your hopes up for a manual transmission.
Mercedes hints at small diesel for E-class at New York auto show: AutoWeek Magazine
2010 Mercedes-Benz E-Class: Leaked Brochure Reveals Interior, Exterior and Engine Details - Carscoop
And I wouldn't get your hopes up for a manual transmission.
Mercedes hints at small diesel for E-class at New York auto show: AutoWeek Magazine
2010 Mercedes-Benz E-Class: Leaked Brochure Reveals Interior, Exterior and Engine Details - Carscoop
