If your iPhone 4 is working fine and not dropping calls then all the 4s really gives is Siri and from what I read up on a tad faster internet. If it was me I would wait for the new one and give it a month so I could get reviews of any issues Apple may need to work on. You cannot tell the 4 from the 4s in appearence. But that just me I have the 4s, keep Siri turned off most of the time and live where the internet is at half 3G service and drops to the "E" a lot.
Love Me Or Hate Me I'm A TechnoGeek, And I Will Express My Opinion! That's What Forums Are For! Sent from my iPhone using iCafe app!YaHoo!