Intel have announced "Atom" best described as a low power x86 core. It is not the fastest out there being in-order, single core and having as fairly low clock frequency. It looks like this could eat ARM alive right? Right?
No! The chip won't be available until next year at the earliest. It still consumes 10 times the power of an ARM and, to top it all, will be pitched at around 40$... ARM have a synthesizable core (very important to the SoC peeps) it has all the SIMD floating point extensions you'd expect in a modern CPU core consumes a 10th of the power of Atom is a far smaller component and, most importantly, can be licensed for a fraction of a fraction of the 40$s Atom is going to cost you.
Yup, maybe Intel can move into this market. Maybe. TBH I'm not sure I see the need for an x86 based mobile device. Do I really want to run full blown office apps on a phone? No. They are just the wrong apps to run. Think email, social networking, games (not Crysis!!!), texting etc.
The UMPC is where the Atom will end up - and whilst the devices are nice they are a fairly niche market - most (the Asus EEE PC for example) end up being used as web terminals (HTML, CSS, IM, bit of flash). In those situations no-one cares what the CPU is (iPhone is _not_ x86 and it's not as though you'd notice).
There's one app that everyone would like on their UMPC's and smart phones... Flash. I'm not a huge fan but it's the only sane way of getting video and audio playback in a browser style application. I think this says more about the shoddy state of multimedia support in the W3C's specifications - Many things have been done well (HTML itself, Form, SVG) and we have some well supported extensions such as the Canvas object. But... Please get a move on with audio and video. Audio especially - for VI users it would be a god send.