VPN or Mobile Private Networking?

Companies are going Wireless and adapting Mobile Workforce to reduce cost and increase efficiency. Is VPN seamless and pervasive enough to satisfy the needs of these folks?

How would the market react if a solution (software client and server) equivilent to a VPN and can render seamless and pervasive mobile computing, keeping connection up in all living spaces to the Enterprise Intranet pervasively and transparently without killing the application while changing communication medium (eg. 802.11x hotspots, 3G, GPRS, GSM data and what have you)?