Willcom's D4 has been hailed by many as the UMPC that could finally bridge the gap between the ultramobile PC platform and the smartphone (at least if the price is right). The lucky guys at Akihabara happen to be right next to Willcom's office in Tokyo, and managed to borrow a D4 alpha-prototype to see just how well Vista runs on a super-compact 1.33GHz Centrino Atom Z520 CPU device with a mere 5-inch 1024x600 TFT touchscreen.
Turns out, on this unfinished prototype Vista is still a bit of a drag, and the Akihabara guys are still skeptical, like many, about how well suited to low-powered ultraportable devices the OS really is. According to Willcom, an XP version of the D4 is "very fast" in comparison. They've still got work to do on tweaking the software to suit the hardware, so final production versions will be better, but Microsoft's limitations on what systems XP can be installed on are looking more and more short-sighted.
The D4 is undoubtedly intended for Japan - it uses the 1-Seg mobile TV standard, and relies on a W-SIM card for the cellular gubbins - but it's also available for import in the US. The stumbling block, though, remains the price: $1,526. If Willcom can develop a non-Japan version, with HSPA and a different type of TV, for a more competitive price, this could be a real stormer of a gadget.