I think, in their ideal scenario, they'd trade for Upton, sign Fielder this offseason, and have Harper win the RF job next spring. Oh yeah, get Strasburg back healthy as well. That would be one hell of a team.
Upton CF
Harper RF
Zimmerman 3B
Fielder 1B
Werth LF
Espinosa 2B
Ramos C
Desmond SS (Though he'd probably be involved in the
Upton deal, so insert some random FA SS)
Strasburg
Zimmermann
Lannan
Marquis
Hernandez
The back of that rotation won't scare anyone, and I don't have a clue as to what else they have in the minors, nor what will be on the free agent market, but they are building a solid team there.