CPU intensity will not be an issue very, very soon. Think about it...when scientists first started sequencing the human genome, they only completed a very small (something like) 0.1% in the first year. Many people doubted that it could be completed in the 10 year timeline of the project. But, given that computing power was (and still is) increasing exponentially, the majority of the sequencing was easily completed in the final years.
Many people (including slashdotters) take a linear view of technology, and make claims that computationally intensive tasks such as "life emulators" are not feasible. In reality, technology builds on technology builds on technology, which in turn yields exponentially increasing capabilities. What might not be possible given 2007 computational power will be abundantly possible in 2017. Building on this exponential growth line of thinking, tasks that are not possible by 2017 standards may be abundantly possible by, say, 2020. The curve is steepening.