Had I not opened the beta version I had and saw that Lightroom 4 is now available online (from Adobe and others), I'd have bought this. At £103 it's a bit more expensive but then it's the latest version. Wonder if Amazon are trying to get rid of Lightroom 3 at a discount before launching 4.
Just playing devil's advocate here as I don't own this software (yet). My point is that newer versions of popular software don't always represent good value for money. The developers have to try and keep a product "fresh" by issuing constant new versions with new "bells and whistles".
In my experience this isn't always a good upgrade for the consumer. Examples that come to mind (in my personal experience) are Microsoft Office, Diskeeper and particularly uLead Video Studio that I updgraded from v8 to v10 only to take it off and re-install the original as it had become too complicated and created hundreds of useless "event" files all over my hard disk.
Of course if you are buying a piece of software for the first time by all means buy the latest as it will have a longer support period, but beware the "bigger better faster etc etc upgrades just for the sake of it.