Recently, a friend approached me with a short question that has a much longer answer.
"Do you think it's really worth it to upgrade to the i3 Core processor?"
The computing industry has really stabilized over the past 5-6 years. We (collectively, humanity-wide) have bumped up against some really hard-limits in computing recently with heat management and silicon manufacturing techniques, resulting in the push to parallelize processing more: more cores, lower clock speeds, bigger caches, extracting more per clock cycle with less waste, reducing heat output and power requirements, etc. It's been a boon for data centers, as the average cost of running these things has actually flattened out. Power requirements, while not going down, are not going up exponentially just like CPU speeds were for a while. And the power cost per GHz of CPU speed, and per GB of storage, is of course going down as we squeeze more performance per kilowatt-hour out of the systems.
So really, over the past four years, that has been the #1 improvement in CPU tech: extracting more performance for the same amount of power. Not extracting more performance as an absolute measure. Also there's been a push to integrate Graphics Processing Units into the CPU core to enhance performance. As a result, it's brought 3D gaming capabilities into the mainstream of computing, with lots of applications in real life that most of us rarely explored before. In addition, virtualization of operating systems has taken off like never before, as we can stuff more and more CPUs into the same form factor with similar power requirements. Even desktop users are very commonly virtualizing entire operating systems on their laptops these days. I know I do; I'm running a Solaris VM and a Linux VM on my Windows laptop at this very moment.
For the home user, though, if faster integrated graphics and extracting more work per clock cycle with better battery life tickles your fancy, then yes, an upgrade to a Core i3 (mobile), Core i5 (Desktop Mainstream), or Core i7 (high-end computing) processor is on your radar. Also, niche markets like audio-visual recording and real-time processing can take advantage of this sort of parallelized-power, if you will, driving innovation in the computing industry today. If power consumption isn't much of a concern and you prefer discrete graphics, or if you aren't running applications that can take advantage of symmetric multi-processing, then the i3 may not be worth the upgrade for you.