This is a fantastic package that I'd highly recommend to anyone getting started with microcontroller programming. The book is substantial, and the parts included are used to their fullest potential.
HOWEVER---------
I love SparkFun for their original products, but I feel that they overcharge for certain things that are quite abundant (for example - nobody should ever pay 15 cents for a 1N4148, a part which is frequently priced out to tenths of a cent). This is one of those situations. What's especially interesting is that not once in the description does it say anything about Parallax - the maker of this kit - giving the impression of exclusivity. SparkFun has marked this item up by 50% of its value - that's OK for small components that are a dime a dozen, but for an $80 kit, this is unacceptable. If you are looking at buying this kit (which, again, I highly recommend), DO NOT BUY IT FROM SPARKFUN. Frys.com part number: 5229667

I was forced to purchase one of these for a class about 2 years after I had become proficient with a REAL micro-controller. What a horrible experience. I don't recommend this expensive, under-equipped product to anyone. Purchase and support the Arduino at minimum. Need more convincing? Stamp replacement chip: $49.95 Arduino replacement chip: $4.95. And believe me, if your new to this, you will eventually be purchasing a replacement.

Missing the "USB to Serial below"

Just buy a PICAXE and use the free downloads at parallax.com for examples and guides. The syntax is similar. PICAXE manual is very good and does a great job at explaining the syntax with a quick example. I went from STAMP(self taught) to PICAXE(self taught) to 68000(school, assembly programming) to Arduino(school). I am planning to learn PIC next using assembly and C. But in my opinion, the PICAXE is best thus far. If you need negative numbers and bunch of libraries, go to Arduino, other than that, grab PICAXE. Just stay away from STAMPs, they are overpriced.

I bought this two(?) years ago from RadioShack for $90.00. It had the same price tag as here, but I had a $10.00 off coupon. I have to say, I do not regret it. It got me more interested in microcontrollers. However, I bought the Arduino last year. I like the Arduino (which is Uno, BTW) better. Namely because it's syntax goes right along with, and very close to PHP, which I am heavily into. I also find that Arduino has support for many more things. The BS2 kit has many cool things, whereas the Arduino kit has very little.

Bottom line: If you are new to microcontrollers, get this kit. But if you are looking for more advanced stuff, like LCD's, voltage sensing, etc, go with Arduino.

Yes the book which comes with this is excellent as is the support on the Parallax forums web site. Several software and electrical engineers over there answering questions and well as many quite knowledgeable people.
I've taught several people, who have never done any programming before, how to do some simple programming with the Basic Stamp. I put up a simple blink LED's program, then in 10 or 15 minutes, they were modifying the program to blink the LED's at different rates.
One guy was adding LED's and adding additional programming after about an hour of fiddling with my program.
Parallax provides sample programs for everything as well, more on their forums, and you can always ask for help. See the BASIC Stamp category in their forums...
http://forums.parallax.com/forum.php
Anyway I recommend the Basic Stamp as the best starting point to learn to program microcontrollers. Then you can more easily move to other microcontrollers from there.

I have to agree the Arduino seems far better value plus the Duemilanove has a built in USB so you don't need a converter or a really old PC that still has RS232 on it. I don't have extensive knowledge of programming but the Arduino is dead easy to program.

I would recommend anybody getting into microcontrollers to use the Arduino, but I will say the book that comes with this kit is really good. I would recommend the book with an arduino board instead. You can download a free PDF of the book from parallax. Lastly, check out the Parallax website they have some really good sensors.