As an iOS Developer, how can I avoid upgrading to Lion? I have been an iOS developer for quite some time now, and I am still using Xcode 4.2, because the new version is now only available for Lion. My problem is that after reading the reviews for Lion in the App Store, it looks like Windows ME would be a great OS compared to Lion.

I really would like to code for iOS 5.1 and above which you can only do with the new Xcode, but I really really don't want to upgrade to Lion. Is there any possible way to avoid this?.

I currently own a 17" MacBook Pro with a Core i5 at 2.53 GHz and 4 GB RAM it runs Snow Leopard great, but I am afraid it will have problems with Lion, not only because of the hardware, but because it seems to be full of bugs and is just slower overall.

I suppose I could install both Snow Leopard and Lion?. Any workaround is welcome.
You really can't. Unless you skip to Mountain Lion. It's one of the blessings and curses of being an Apple Developer and that is that you must stay current, or you're out of the game for both iOS and Mac Development. 

To use the latest bells and whistles for the next OS releases, you are really going to be bound to Apple's software and hardware requirements for those tools, otherwise you will find yourself spending too much time hacking together your build tools, instead of making forward progress.