Don't count on it. FYI the U3 platform is already being revised heavily and
Microsoft is one of the partners working on it so don't bet on this U3
thing.
http://news.digitaltrends.com/news/story/12967/sandisk_dumping_u3_in_favor_of_microsoft
Why, according to you, would Outlook lose it's market edge if it isn't
turned into a U3 application?
IMO it wouldn't add much. The thought behind it will always remain data
availability and there are a 1001 and ways to have your email, contacts,
calendar etc remotely available to you especially when you consider that
Outlook is targeted to be used with Exchange.
Having specialist software like from AutoDesk being U3 compatible would add
much more if you need to work and/or present remotely since those
applications aren't commonly installed and you wouldn't have access to your
data.