Hackers, or more accurately well skilled programmers, have already ported Siri to the iPhone 4. Currently they don’t have the graphics drivers working yet, so everything is being rendered by the CPU (hence the slow response time).
Shane is the founder and Technical Editor-in-Chief here at That's It Guys. He enjoys Star Trek, 80s and 90s action movies, and everything tech related. Shane is highly skilled with computer hardware, software, and electronics.