This is my take on things, although others probably will have a more qualified opinion.
I've listed the players who have/had a decent or outside chance of making it at United, and have given them a score based on that.
1985:
Dong Fangzhuo - 2/5 - He still has some way to go before he's ready for the first team. Right now he seems to be on the same level Bellion was, albeit probably a better finisher. I'm assuming he'll be sent out on loan next season, so that will be some valuable experience for him. It's always going to be difficult for Dong to have a long-term future for him.
Chris Eagles - 1/5 - I'm impressed by how well Eagles has done in a central midfield role for the reserves, although making the step up into a first team midfield is always going to be far more difficult. He seems to have the talent and the skill to make it at a good Premiership side, but so far his loan spells have been far from eyecatching. The clock is ticking for Eagles' United career, and I don't see him making the grade.
Phil Bardsley - 2/5 - Bardo did will when he was asked to deputise for Neville last season, but IMO he doesn't have the ability level required to make the position his own in the future. Brown is still fairly young, and at this stage in time he's probably a better option than Bardsley for the rightback berth. He'll probably be sold to a Championship or Premiership side this summer.
1987:
Giuseppe Rossi - 4/5 - Rossi IMO was a dead cert to make it last season, but after his unfortunate loan spell at Newcastle and failure to get first team chances at United, I think there may be a chance of him wanting to get first team football elsewhere. In terms of skill level, he's definitely up there amongst the best reserves we've had in recent years. My only concern is how well he adapts to the physical nature of Premiership football.
Gerard Pique - 4/5 I don't know if he will be able to handle the Premiership as a centreback because of his relative lack of pace and aggression. However, he's versatile enough to be employed as a rightback or a DM, and he definitely has excellent technical ability.
Fraizer Campbell - 2/5 -It's always going to be difficult as a striker to break into the United first team. However, if Campbell can secure a loan to a good Championship or Premiership side next season and impresses, he may have a chance of making it. He's quick, brave, strong for his size and scores plenty of goals - Les Kershaw likened his playing style to Mark Hughes, and coming from him that's praise indeed.
Danny Simpson - 2/5 - He's a quick attack-minded fullback who IMO has a decent enough chance to make it if he does well with Sunderland. His size is a bit of a problem, but if Evra can eventually bed in then Simpson should have no problem. Of course right now the number of defenders we have in the first team squad will be the main concern for him.
Flo N'galula - 1/5 - Injuries have really taken their toll on him, and he still has some ways to go before he's even at the level necessary for a United player. However, there's rumours of him going on loan ot Antwerp next seaosn, so if that materializes and he does well there, he may have an outside chance of making it. The advantage for him is that he plays in a position that United have very little cover for.
Darron Gibson - 3/5 - Fergie seems quite impressed by him, and Gibson seems like he has the tools to make it. Unfortunately he doesn't seem to be setting the Belgian second division alight, and it just shows that he is still a step or two away from breaking into the first team.
Lee Martin - 2/5 - He's been one of my favourites to make it for a couple of years now, but unfortunately the last 8 months haven't been the best for him. Had he done well at Rangers it might have been a huge boost for his first team chances here, but now he is even struggling at Stoke.
1988:
Jonny Evans - 4.5/5 - IMO he stands the best chance of making it. Several of our players do very well at reserves level but when it comes to making the step up to a higher level they don't seem to perform to the best of their ability. With Evans' he has been impressive playing for the reserves, at Antwerp, in preseason for the first team, with N.Ireland, and now with Sunderland. His biggest challenge now will be staking a claim for a spot at United ahead of United's second string defenders i.e. Brown and Silvestre.
Jamie Mullan - 1/5 - Mullan has been very impressive for the reserves this season, and I like the fact that he plays as a traditional winger hugging the touchline. However, he just doesn't strike me as someone who will eventually be able to make the step up to United's first team. He may very well go on to have a successful career with a Championship or even another Premiership side. Yet, he still has time on his side so I wouldn't write him off.
Kieran Lee - 2.5/5 - I think Kieran stands a good chance of making it. He's got a terrific attitude and is extremely versatile. I don't know if he will ever have the ability level to be a regular for United, but time is on his side and he seems like he could be a useful squad member in the distant future.