Fairly simple question so I'll keep this post brief.
In my opinion: yes, Santana deserves to be in the Hall of Fame someday (though I'm such a homer I think Brunell should be in there too).
Just a glance at the Redskins Receiving Records page on Wikipedia (about 2-3 seasons out of date) tells you he's one of our greatest players. His career receptions total is up to 609, which ranks 3rd best all time. And let's not forget he's second only to the legendary Art Monk in the single season receptions caregory, and that he holds the single season receiving yards record at 1,483 yards in the 2005 season.
Other than that he's an explosive, reliable, tough dog of a player, and--for many people--one of the few bright spots in an otherwise dull half-decade.
That's my take, at least. Every time I bring this up to non-Redskins fans they look at me like I'm insane.
Tell me what you think in the poll or in the comment section, hail!