They're kind of like flight paths in wow. Only instead of having to wait through a flight that's long enough for you to go make a sandwich and still have time left to eat it, you travel there instantly. They also seem to be more prevalant than flight paths in most games, so it should put you fairly close to where you want to go.
Flight Paths: Mandatory video cut scenes that last several minutes and the player will have no option but to watch in the middle of their play sessions 100's-1,000's of times across the life of the game. How could that ever get old? /sarcasm off I don't see where they would "need" mounts given the waypoints but they could add a little bit of convenience. I bet they would be highly useful in WvWvW right? They shouldn't have waypoints in WvWvW or people could teleport behind your lines like a bunch of startrek ninjas. The other option is to make mounts like the "Golum Suit" with its own abilities or buffs, more of a combat mount.
I agree that there should be no flying mounts. Releasing mounts in an expansion is a good idea though. I think their expansions will give way more to the players then GW1 did.
I found this on a FAQ, answered by Anet.. "Will there be mounts?" Anet: " Other than map travel and asura gates, there will be no other methods of long distance travel such as mounts, ships, etc in Guild Wars 2 upon initial release." So it might be coming with an Expansion that is still an possibilty i think.
i was looking at vids of some other mmo with ship to ship combat. it didn't look very well done but the concept was cool.
Loathe mounts. There's nothing more awesome than charging down a hill on foot with a group of people as you crash into the enemy.