Jason Witten seems to be highly regarded among fantasy football enthusiasts for 2008. For example, Brandon Funston at Yahoo! has Jason Witten ranked 43rd overall, the top tight end on the list. He did have 96 receptions for 1,145 yards and seven touchdowns last season, so he should be highly regarded.
Funston has Tony Gonzalez ranked 54th overall, the fourth tight end on the list. But last year, Gonzalez' numbers were very comparable to Witten's: 99 receptions, 1,172 yards, and five touchdowns.
It was Gonzalez's seventh season in the last eight with 900+ yards. He's consistently produced at the tight end position. Why shouldn't Gonzalez be ranked ahead of Witten?
Witten does have better team context for support: he's got a good quarterback and a high scoring offense, while Gonzalez has neither. But Gonzalez has been a great tight end for a decade, with all sorts of good, bad, and mediocre quarterbacks--I'm not sure there's significant data to suggest Gonzalez will struggle to put up numbers with a lesser QB. Witten will get more help from his teammates, but that doesn't mean his numbers will significantly outpace Gonzalez's.
Witten did have more touchdowns than Gonzalez in 2007. But in the last four seasons, Witten has 20 TDs, Gonzalez 19. That's not a significant difference to suggest Witten will score more TDs than Gonzalez in 2008. After all, in his career, Gonzalez has matched or betterd Witten's career high of seven touchdowns in a season five times (furthermore, Witten played most of 2006 with Tony Romo, and only had one touchdown).
Jason Witten has established himself as a good fantasy tight end over the past four seasons, certainly. But the current perception values Witten, while people seem to have grown bored with Gonzalez' consistently high production. That makes Gonzalez the better fantasy pick--I would rank them very close together, but Witten will likely go a round or two before Gonzalez. While somebody else is drafting Witten, you can draft a quality RB, WR, or QB, and try get somebody like Gonzalez a bit later. Witten is good, but are you that confident he'll have a better year than Gonzalez? Than Antonio Gates? Than Kellen Winslow Jr.? Than Chris Cooley? So is it really worth selecting him before any other tight ends have been picked?
I never like taking a TE early in a snake draft--it requires you to pass on a potential starter at one of the more critical positions (RB, WR, QB). And I always like drafting those players that are so consistent over a long period of time that other fantasy football drafters have started taking them for granted.
(The standard caveat applies: Hazelweirders must speculate whether I actually believe any of this).