Yes, but you are assuming that the microcode between the two systems is the same. I do not believe that is a good assumption to make. Just becasue they use the same CPU does not mean that the BIOS uses the same mechanism for identifying the CPU and understanding its capabilities (stepping, voltage, multiplier). For example, some laptops out there (I believe some Dells) do not require any modification to the BIOS at all. All you have to do is pop in the faster proc and it works. Others, like the Toshiba, require a microcode update. Other laptops (perhaps your Sony) do not have any microcode utility and require a completely different BIOS file to understand the different proc. In short, you need to find out a heck of a lot more about your system's BIOS and how it differs on systems with different procs. I would not advise you to use the microcode from the Toshiba unless you can verify using a hex editor that the Sony BIOS contains the exact same microcode.
Messing with your BIOS is not something to be taken lightly. You definitely don't want to be screwing around with it unless you know what you are doing. The people that have participated in this thread (including myself) have a certain measure of expertise and have taken some great risks. Our research and (to some degree) luck have resulted in a very measured, calculated risk that I was comfortable taking with my system. Unless you are willing to take the chance that you may "brick" your laptop, you should not be the first person to try this on your system without some serious foundation for a belief that it will work.
Just my $.02.