So played a bit in the spring, then played with my son in July, and then a little bit over the past few months, on the official UO shards.
Impressions.
The event they held over the summer was pretty fucking cool, and it was a demonstration of a new quest/event/dungeon system that was just implemented.
The "New Legacy" speciality/seasonal shard is cool (the rewards are worth it). It's also the test-bed for new code that's being written to replace the old "spaghetti" code.
Atlantic completely, utterly sucks ass. A decent-sized house in a decent location (not even max-storage mind you) runs into the hundreds of millions. With that said, you can place 9x14s and 10x15s here and there when houses fall (Ye Olde IDOC) but there's always a dozen people also trying unless you stay up really late. But Atlantic is over-run with middle-aged 12 year-olds talking shit to each other in general chat, and the best housing plots that are available were placed by scripters who had automated bots place the micro-second an IDOC spot was available for placing. Apparently 1-2 people have placed about 90% of the best spots that have opened up over the past few years. Developers say they are going to deal with them harshly, soon (2 weeks?). Prices also suck on a lot of things, and it seems to be populated by shit-talkers, item collectors, and people trying to sell stuff for real-life money.
Lake Superior, Catskills, Chesapeake, Baja, Pacific, and the Japanese shards are the best shards - not as much activity as Atlantic, but not overrun with shit-talking and scripters, and you can place 18x18s (And even towers and keeps). They ran the events this summer just fine (the events required cooperation from several players to even have a shot at making it through all 5 steps).
Luna no longer matters as far as housing because we have a shard-wide vendor search system you can access from your home or in a city. People still hang in Luna a bit, because the bank has all of the NPC shops around it, but it's not like it was.
According to a friend who has gotten me re-engaged with UO, UO is slowly being rewritten to address various issues (it has 5-6 person team doing coding/design/graphics). This summer, the back-end of the Classic Client was migrated to "modern tools" (guessing the same as the Enhanced Client). Right now they are working on making the Classic Client run at 60fps or more, and with a resizable window.
If you are wanting to play production shard, I'd go with Lake Superior. I'm on there and can help anybody who is interested. It seems to run on a central time zone, and the reason why I originally picked it back in the 90s was because of how many Austin-area players were on it (it had a really good ping, I think it was located in Origin's offices here in town). Yeah, there's Lake Austin, but that came later.