Matthew 25: 31-46 is an interesting section. I've often seen it used in justification for not all those who call on Jesus's name will actually be saved, and it proves the existence of a hell in referring to an eternal fire.
I think both viewpoints miss the purpose of the chapter.
First -- with the sheep and the goats (is there a signifigance to picking goats? Sheep I understand, given all the Shephard references). If this is combined with Matthew 7: 21-24, one category alone determines everything: helping the less fortunate. As much as the emphasis is on grace and faith, works do matter. They really do, because it's the very thing that makes the sheep be sheep. It's even more interesting with Matthew 7: 21-24, because prophecies and casting out devils and doing wonderful works in Jesus's name isn't always enough. Actually, it's almost like Jesus doesn't matter at all in terms of salvation, according to Matthew 25.
Second -- the sheep are surprised that it was a qualification, as are the goats. It's almost as though the matter of salvation is a surprise for everyone. Which, actually, I really like what that says. It means the sheep didn't act kindly out of a sense of reward, but they simply acted kindly. I recently ran across as website that asked if people wanted to be sheep or goats on the day of the Second Coming. If we want to be sheep and get into Heaven, then we must make sure to do kind things to the less fortunate. Doesn't that reduce the kind deeds to only doing them to ensure you get something out of them -- to avoid Hell? That makes doing the deeds completely selfish, of which there was no element in Matthew 25.
Third -- who are the less fortunate, exactly? Are they the sheep or the goats? Really, it almost seems like there are three groups here -- the sheep, the goats, and 'the least of these.' Are 'the least of these' goats or sheep?
Fourth -- Jesus's identification with 'the least of these.' The inference here is that whenever the sheep helped someone, they were helping Jesus. Jesus identified with 'the least of these.' Truthfully, hasn't every single person been 'the least of these' at one point or another. If Jesus is seeing himself in the 'least of these,' then would he really cast some people into an eternal fire? It seems like Jesus identifies himself with all people, period.
Therefore, I think the point of this section of Matthew 25 has nothing to do with hell or the Second Coming, but rather to make one aware of how connected we all are, and how connected God is to everyone. It's to reduce selfishness.