So far on Mavericks DP2 I have used successfully all the Apple apps such as Mail, Safari, Maps etc.
I have also used with no issue:
Parallels 8 with Windows 8.
Final Cut Pro.
Aperture.
Tweetdeck.
Office 2011 including Outlook connected to DavMail/Exchange 2003.
Geekbench 2.
uTorrent.
Evernote.
Pages.
Bitdefender.
Coda 2.
World of Warcraft.
iA Writer.
Clear.
Pixelmator.
Wunderlist.
VLC.
Think or Swim Share Trading Software.
All work fine and zero crashes or errors in Mavericks itself, hope that helps.
I upgraded from Mountain Lion as well with all those apps previously installed.