This was in another thread, but better to answer it here since this one's closer to the topic.

Initial GW cost is really high though.. and once you get level 20 all you can do is play PvP.
Not quite true. Over a third (some say half, but I guess it's debatable) of GW PvE content is for Ascended (level 20) characters. Leveling stops at 20, and you can also get statistically "perfect" equipment around ascension, but character development continues in the form of skills to be acquired and *gasp* getting better at playing said character.

According to Arenanet, up to 80% of GW:Factions content is for level 20 characters, and Factions is supposed to have even more content than Prophecies (the first GW chapter.) It may sound a bit controversial to players who are accustomed to level grinding and collecting equipment, but for those who would rather outwit and outplay opponents instead of having an advantage in "level" and "gear", Factions will be a good title to pick up.

BTW, I have more preview access keys to dole out if Saturnus and Snowhobbit run out...