I so this routinely and have never had any issues. A normal sequence would be ESB, porter, then robust porter or dry stout, oatmeal stout, imperial stout. I will do 3 beers without ever opening the fermenter. The biggest issue is temp control because racking wort onto a huge pile of yeast will make the fermentation go ballistic if you can't keep the internal temperature under control.
It's always time for a beer
On tap:Crabapple Brett Blonde, Cherry Brett Blonde, Rye Stout,Sour Porter,Oatmeal Stout, Amarillo Wheat, Saison, ESB
Primary:Pecan Smoked Roggenbier
Bottled:2006 crabapple cider,Cherry Brett,Black Braggot,2 Prickly Pear Meads(1996 and 2006),Sour Pumpkin
Lagering: Pecan Rauchbock
Secondary: apple cider vinegar
Next: Porter/Vanilla Bourbon Porter,