Intel is getting pretty close. in a benchmark of a medfield phone, battery capacity for web browsing was just 20% lower than the best android phone benchmarked[1].
And medfield still uses 32nm process,not the latest finfet 22nm process intel is so proud of.
And the orange san-diego is also priced reasonably at $300.
The real question is "How little are Intel willing to sell the CPU in this phone for?".
A fairly up to date Cortex-A8 ARM CPU can be had for under $5 [1] and as impressive as Intel's manufacturing base is, their profits are based on selling CPUs at 50-100x higher prices than this.
Whatever happens, I think the coming battle between generic ARM chips and x86 is going to slash Intel's profitability.
ARM are completely dominant in this market.