Avalon 3D has always suffered from aliasing problems.  Consider the following 3D mesh, from the ZAM3D default library:

The jagged edges of the geometries are harsh on the eyeballs.  With the September CTP of Avalon, this is no more!  While not all video cards support anti-aliasing, tier two cards do support it.  While the Avalon team hasn't yet posted a complete breakdown of which cards do and don't support anti-aliasing, most cards that support DirectX 9 will be able to do anti-aliasing. With anti-aliasing turned on, you get something like this:

Much better! Now, here's the trick: anti-aliasing wasn't turned on by default in the September PDC build, so you will need to download these registry keys to turn it on.  Note that there is a different registry key for XP and Windows Server 2K3 (xp_aa.reg) than for Windows Vista (vista_aa.reg)