As a pre-orderer I've only got access to play Beta2 recently. Over the weekend I've played extensively, finishing a Spell of Making and a Domination victory respectively. I'll try to give a concise overview of problems I've encountered:

Visual

• many still screens (application load, saved game load) and the victory cinematics are stretched on my widescreen (1920x1024) rather than have some form of aspect-ratio respecting display. This is a pity, as other screens (like the rendered main menu) look lovely.
• it would be nice to have higher resolution/definition images for still images, as they feel just a bit washed out
• in-game when pressing [Escape] to get to the options screen, the mouse cursor used depends on the mouse cursor used at the time, for example it is two-crossed-swords when having hovered the mouse over an enemy unit at the time
• small detail: in-game at the top-left the season/time indicator ("Spring 341 A.C.") changes size based on the string it is showing (variable-width), this makes the research bar hop left and right if you go through a quick succession of turns. It would be nicer if the season/time indicator had a static width

Application Restart

• after exiting the game, it isn't immediately possible to restart the application; the cursor shows busy for a moment or two and then nothing happens. (I'm guessing this is either due to the prior memory space still being resolved, as I get memory leak errors; or possibly be a side-effect of the game sending information like crash-details back to Stardock)

Save-Load

• the game is prone to crashing when loading from in-game rather than main menu. I believe Frogboy mentioned this previously, but I was under the impression it was fixed for Beta2

Quests

• spelling error in Haitan's Summon: "You have kiled the elemental and recovered the staff, return it to Haitan"
• I've experienced several uncompletable quests - unfortunately I did not note down their names, I do recall one requiring me to kill a dragon (and giving me a dragon killing spell) but I could not locate any dragon to go with it

General

• I've received the same technology message from a PC-faction repeatedly (apparently they've achieved the enlightened knowledge of "literacy" three times)