FanGraphs' release of the following season's ZiPS projections is always fun. Standard disclaimers: these are projections; they are merely highly educated guesses; etc.
Basically, ZiPS thinks the Pirates need another starting pitcher and first baseman, but that other than that, they're going to be really good. Andrew McCutchen, Starling Marte and Gregory Polanco are projected to account for about 12.5 wins all by themselves, more than last season. It's bullish on a bunch of the Pirates' prospects and depth players, including Alen Hanson (whose top comparable is Jose Reyes), Tyler Glasnow (top comp: A.J. Burnett), Austin Meadows, Keon Broxton, Jake Goebbert, Danny Ortiz and Cole Figueroa. And it likes the Bucs' bullpen.
ZiPS isn't a huge fan of Michael Morse (projected WAR: 0.2) and thinks Jon Niese will be only ever so slightly better than Jeff Locke. So the system seems to broadly agree with most Pirates fans that there's still some work to do. It does, however, suggest that what the Bucs already have in place is pretty promising, perhaps moreso than we're inclined to think given the Pirates' offseason moves so far.