I've heard of them, both played with D'angelo as well, Hidadalgo on Spanish Joint, i think, and Gadd on the New Years Eve Special with D'angelo back in 1999 with Sanborn Eric & Marcus.

I wonder why Eric & D'angelo never collaborated much after that?

D'angelo recently came back from Eric Clapton's drug treatment facility in Antigua, as i read here.

Marcus and D'angelo would work, well, Marcus & anyone would be superb. Marcus & Meshell N'D geocello worked., Marcus & Rapheal Saddiq worked. Marcus & Luther Vandross worked, Marcus & Bill Withers worked. (Watching you Watching me)

I guess we'll just wait and see what D'angelo and the good Dr. blesses us with.

Their musical history between the two of them alone is rich, and should yield some intruging results.