Been playing this some more.
It's still PSO, there's no doubt about that. Still, it's pretty much the culmination of all the different versions, what with all the different quests (both single player and online), both Episode 1 and Episode 2, the Battle/Challenge modes, etc. It also appears they're adding even more content - the patch I downloaded had something about a new boss monster, so they might be adding more maps/monsters/etc. I've only played Episode 1 Act 1, so that's the same old noob stuff.
They've also improved the interface - there's a hotkey bar. Yes, you can select any item/skill/attack and hotkey it with numkeys 1-0 and use it instantly. Yes, you can FINALLY have more than 6 attacks conveniently available. No more choosing between a nuke, buff, debuff, or item with that last slot - you can actually make use of those 10 hotkeys, as well as the traditional 6 skill slots. Playing a Force seems viable now, especially since that class got a buff from old-school Dreamcast PSO in the first place.
From what I've been able to figure out, it should be cheap to get into, as well - beta characters will carry over into retail (within a certain time period, anyway), so characters you make now will carry over past the open beta period. It also seems like the client will be a completely free download (no buying a retail box for $30 or more) and will have a 15 day/20 level trial, so there's no immediate obligation to buy (the Korean MMOG paradigm, rather than the US one). The monthly fee seems to be the standard $9 that they've gone with ever since PSO version 2, so that's nothing new.
I dunno if I'll continue beyond beta, but PSO still has that certain charm to it, and the price is certainly right. With the improvements to the interface (god, I love the hotkeys), it could be worth picking up again, even if it's still essentially Space Diablo.