I think 5 years is a pretty good amount of time to review a draft class. That would put us at 2008 (well, it's 4.5 years, but close enough for me).
1/19: Andrew Cashner
This pick has worked out relatively well, all things considered. Cashner had definite starter potential, and still profiles as a really good closer. Unfortunately for him, he's very injury-prone, and likely will be for the duration of his career. He's an intriguing guy, but the Cubs spun him for the even more impressive Anthony Rizzo, who looks to be the 1B of the foreseeable future.
1s/41 Ryan Flaherty
The Cubs lost Flaherty to the Orioles in the Rule V draft last year. While Flaherty never developed into a top-flight prospect, he was fairly intriguing due to his power from a MIF position. He looks to be a future utility guy, or a bench bat with some power. I don't expect much more than that, though there still is a ceiling of a productive every day player (that he is unlikely to reach).
2/65 Aaron Shafer
Swing and a miss. The righthander from Wichita State (go Shockers!) never got past AA, and after a year with the Atlanta system ended up pitching for Fargo-Moorhead in Indy Ball.
3/97 Chris Carpenter
The Cubs "spun" Carpenter into Theo Epstein, so I'm happy with it. He's another flamethrowing bullpen guy, but he got hurt as soon as he left the Cubs and ended up on waivers immediately afterwards. He cleared waivers and will start the season at AAA Pawtucket; he'll need to work on his control while rehabbing from his injuries.
4/131 Matt Cerda
Cerda was an intriguing 3B rising through the ranks until the Cardinals took him in the Rule V Minor League Phase this year. He's short on pop but looong on plate discipline; he just seems like he's going to be an unheralded find for the Cards in a few years. I liked his game when he was a Cub, though, and I'm cheering for him even if he's a Cardinal. He needs to find at least 100 points of slugging to be a real threat.
5/161 Justin Bristow
Stalled out in A ball.
6/191 Josh Harrison
The Cubs traded Harrison along with Jose Ascanio in 09 for Gorzelanny and Grabow. It was a good trade for the Cubs, and Harrison ended up being the 25th man on the Pirates roster last year (and likely this year). He can play every position except pitcher and catcher but he has little power and less discipline, so he's going to struggle to stay on major league rosters for very long.
7/221 Luis Flores
Flores is still toiling in the Cubs organization as a non-prospect. He had a nice season in 2011 (.248/.335/.504) but he's never played much for whatever reason. Maybe at some point he's a backup ML C, but I doubt even that.
8/251 James Leverton
Leverton was released in 2011 by the Cubs but I have no idea why. He wasn't anything special but he was a (relatively) recent draftee who looked to start is age-25 year in AA ball. No huge loss, but still surprising. He caught on with Miami after a stint in independent ball and finished last year as a pretty serviceable reliever/spot starter for their AA affiliate. I don't know nearly enough about Miami to know where he stands in their organization, but it wouldn't surprise me given their lack of quality arms if he ended up as a LOOGY some time next year.
9/281 Jay Jackson
There was a time when I thought Jackson could be a serviceable back-end starter. Those days are long past, though, and Jackson just hopes to get to the bigs at some point in his career. He's not likely to break into the pros with the Cubs, though, because he's got a dozen interchangeable relievers ahead of him at this point. He's best off getting released and trying to get a fresh start somewhere else.
10/311 Alex Wilson
The Cubs failed to sign Alex, who was drafted in the 2nd round by Boston in the 2009 draft. He looks to be an option in their MLB bullpen this year.
Other Notable Draftees
13/401 Tony Campana
You already know enough about Campana.
15/461 Casey Coleman
Coleman got roster-screwed this year. He probably deserves a shot in the pen, but he has options and he isn't on the 40-man. I'd expect Coleman to get an opportunity in Chicago again this year.
18/551 Jeff Beliveau
Got a cup with Chicago last year, ended up waived and claimed by Texas. Great minor league numbers and could definitely end up being productive in the future. Kind of sad he's gone.
21/641 Logan Watkins
Ended up as a decent prospect. I'd imagine he's got a chance to join the big league team at the end of this year if things go the right way for him.
27/821 Sonny Gray
Didn't end up signing. Was a global top-100 prospect in the Athletics system in 2012, who drafted him with the 18th overall pick in 2011.
36/1091 Michael Brenly
A favor for Bob, Brenly may very well make it to the big leagues as a backup catcher.
37/1121 Erik Hamren
Apparently saw 12.1 innings of work for the Padres in 2011. Never heard of him.
46/1386 Tony Zych
A power bullpen arm that might end up in the bullpen at some point in the season (and has a darkhorse shot at breaking camp this year, I think).
EDIT: It's been pointed out that Zych didn't sign in 2008 and was a Cubs re-draft. He should count as a 2011 draftee for my purposes.
Generic NPC Names
This was a pretty average/bad draft. The best player they ended up with isn't even a Cubs draftee (it's Anthony Rizzo), but he looks to be pretty great. The Cubs also ended up with a decent utility/2B/CF prospect (Watkins) and a few middle relief profiles (Coleman, Jackson).