Google Earth works, although it's almost certainly not native.
Brand new XP install connected without issue to the XP network.
IM (AOL/Trillian) or MSN (Native Client) didn't connect
PPTP does not work
Youtube videos do not play
Firefox and IE seem fine.
IMAP/SMTP via Thunderbird using SSL/TLS works
Windows Media Player 10 can stream audio (http/mp3) from a native IPv6 web server
Was able to connect only after the following:
Microsoft Windows XP Version 5.1.2600 (C) Copyright 1985-2001 Microsoft Corp.
C:\Documents and Settings\cgrundemann>netsh interface ipv6 install An extended error has occurred. C:\Documents and Settings\cgrundemann>esentutl /p %windir%\security\Database\secedit.sdb ... Operation completed successfully in 5.141 seconds.
C:\Documents and Settings\cgrundemann>netsh interface ipv6 install
C:\Documents and Settings\cgrundemann>
Firefox and IE both working
As expected: no IM (Pidgen with AIM, Yahoo and Google accounts), corporate VPN not available
Downloaded a PDF from APNICs site
Was able to login (both individual and chapter admin) and navigate www.ISOC.org - everything seems to work!
Was able to log in and post to a Word Press weblog hosted by NearlyFreeSpeech.net