Some background: I worked for a company many years ago that built Smalltalk environments. Actually, I worked for that company twice. The first time I worked there, I wrote MacIntosh applications for one of our clients using a combination of MPW and Smalltalk. I left the company for about 5 years when there was a big lull in the business. During that time, my boss built a Smalltalk environment called Agents OS for the MacIntosh. That link will take you to his latest product, which is a system called SmallScript.
Anyway, about 5 years after I left, my old boss called and we got to talking about building a Windows version of AOS. I was newly married at the time and had just purchased a house. But I packed up my 4 computers, all my books, and some assorted other things like clothes into my 4-Runner, and drove to California with the intention to move there because I believed in what he was doing. Unfortunately, due to life-happenings, it didn't work out.
I haven't touched Smalltalk since then, which is a travesty because Smalltalk is probably the most elegant environment I've ever worked in. Squeak is a Smalltalk environment. The group they've assembled for Squeak is like an all-star list of players from the Smalltalk world: Dan Ingalls, Alan Kay, Ted Kaehler, John Maloney, and Scott Wallace.
I played with it all last night, and it took me back to my days of writing Smalltalk applications on the Xerox 6085 workstation when I worked in a small artificial intelligence lab in the late 1980s. It's a really nifty environment with the kernel built in none other than Smalltalk. It has all of the normal extensibility you'd find in a Smalltalk environment. Best of all, the Squeak Team wants to keep it "open" so people can extend it to their heart's desire.
Either you'll love Smalltalk or you'll hate it. Either way, it's what drove the object train.