Only doing part of the filament was also most likely for comparison purposes; the untreated part of the filament was the "control".
Regarding CFLs, you should save your receipt. The current GE residential lineup are guaranteed for 5 years, and I remember the old "Lights of America" ones that were being sold a few years ago were guaranteed for 7 years. I've had to take a few of the old LOA ones back earlier in their model life with no problems; imagine the look you would get when trying to exchange an incandescent.
IIRC, the traffic light bulbs were rated at 10,000 hours... I knew a guy who worked for the public works department, and had brought a few home for use in his house. Output seemed a little less than a standard 60W, but not by much.
In fact, here's a 60W variety that is advertised at 16,000 hours:
http://www.bulborama.com/store/cart.php?m=product_detail&p=698
