The beta fixes many bugs found in previous alpha releases, including the workaround for the nasty IE high-res display bug (filter:none rule removed, IE7 is ok with ClearType fonts).
The beta also adds two new visual themes 'vista' and 'system'. The 'system' theme combines vista, xp, aqua and classic themes into one package so that the theme appearance matches the current user operating system.
The AW 2.5 API is 99% backward compatible with AW 2.0 so in most cases you will not have to modify your code to upgrade to AW 2.5.
The final 2.5 release is expected before the end of this month and the price for the AW 2.5 developer license will increase to USD 495. Anyone who is buying AW 2.0 in the next two weeks will get a free upgrade to AW 2.5 and the same applies to all customers who bought AW 2.0 in the last 12 months (i.e. still have valid upgrade subscription). If your upgrade subscription has expired you can renew it for another 12 months at USD 195 per developer -