It's been pretty clear for months now that the Green Bay Packers will be starting Jermichael Finley at TE in 2010. He'll never be much of a blocker, and Mark Chmura is not his biggest fan, but he has the highest ceiling of any receiver on the roster.
After him, there are four other TEs in training camp, and it's considered to be one of their deepest positions. It's likely that only two of them will make the 53-man roster (with maybe another on the practice squad), so there should be a real battle here this preseason. Another thing to consider is that all five TEs are similar stature (6'3" to 6'5" and 245 to 252 lbs.) so there is no real advantage/disadvantage for any of them in that regard.
TE Donald Lee. A former starter might seem to have the inside job, but he also had a poor 2009 season in which he dropped a bunch of passes. I don't have salary records handy for all of them, but since he signed a four-year extension in 2007, he's probably the highest paid one on the roster, which might be an additional reason to let him go. His biggest asset may be that he's the most consistent blocker, but he doesn't have a lot of upside.
TE Spencer Havner. The former LB made a splash as a TE in his first full-season on the active roster in 2009, but he began 2010 on a sour note by breaking his shoulder blade in a motorcycle crash. He appears to have fully recovered, but it kept him out of most offseason activities. It's hard to tell since he only had 7 receptions last season (4 TDs), but he seems to have good hands. He had some fantastic blocks around the goal line, but he also missed some too.
TE Tom Crabtree. It's still too early to tell, but he's been getting a lot of love so far in training camp. Apparently he's a heck of a blocker too, while they're "working his ball skills" as a receiver. Unless he really shines during the preseason games, he's a real longshot. I'm a little fuzzy on his past before he signed with the Chiefs in May 2009, but I think he has another year of eligibility for the practice squad, if the Packers want to keep him there.
TE Andrew Quarless. If you missed the Family Night Scrimmage last Saturday, you missed him drop a wide open TD catch as he was falling down in the end zone. I haven't read anywhere that he's a great blocking TE, but he's got the potential to be the best receiver after Finley, if he's not dropping TD receptions. He seemed like an odd choice in the 5th round last April, so it wouldn't be a shock if he doesn't make the 53-man roster. If he were released in September, it's very possible that he could be unclaimed on waivers and end up on the practice squad (as OL Jamon Meredith did last year). Of course the Packers eventually lost Meredith to the Bills, but they could always try and keep him if another team were offering him a contract.