TKIP WiFi networks (that work fine with e.g. N9 and N900) seem not to be supported.
Exchange server policy requests (e.g. to enforce a device lock) are seemingly rejected (or probably just silently ignored), ignoring policy is set in settings (and that setting is not changeable).
Email sync with true Exchange server is glitchy, calendar sync is almost fully broken and contacts sync doesn't work (again - N900 and N9 work fine with same server).