The business phone is dead and the industry must now come up with mobile devices that can both work hard and come out to play too, according to Microsoft.
Speaking at the Mobile World Congress (MWC) trade show in Barcelona, Robbie Bach entertainment and device division president said: "People don't think of these as business devices. Frankly they don't think of them as personal devices. These are devices that span your life. They go from what you do at work to what you do at home and so the challenge for us in the industry is working out how to service that broad array of functionality."
At MWC Microsoft announced it has added another mobile maker to its Windows Mobile line-up, meaning it is now doing business with "four of the top five manufacturers".
The device -- the Xperia X1, Sony Ericsson's first and only handset to run Windows Mobile -- was being shown off in Barcelona.
Microsoft also announced it is acquiring mobile software and services company Danger -- maker of the technology behind T-Mobile's Sidekick device -- a company it said "enables an audience of people who want to be constantly connected with their friends" and with their data.
Microsoft's Bach said five years from now mobile will be about "general purpose computing" -- not as a replacement to the PC but rather an addition.
He said: "It'll add to the PC, it'll bring new things to life."
Bach added: "We are expanding the work we do with Windows Mobile to expand the picture -- to reach out beyond your work life, into your personal life so that one device can carry you from start to finish... Just like the PC has a broad array of things that span what you do at home and what you do at work your mobile devices will enable you to do the same thing."
Nokia, meanwhile -- the world's number one handset maker -- remains outside the Windows Mobile party. Microsoft would not be drawn on the question of when -- or if -- it will be able to add a fifth string to its Windows Mobile bow, saying only that it has "a big relationship with Nokia at multiple technology levels" and "a lot of discussions are happening".