I'm not sure how to explain this without getting into Jasper jibberish.
I think there's been three generations of XBOX 360 hardware: Zephyr, Falcon, and now Jasper. Perhaps you've heard that XBOX's have a rather high failure rate, the old "red ring of death". Well even though it's too soon to tell, the newest Jaspers should sport components that are less likely to crap out. They also come with 256mb onboard memory. That's why everyone would prefer to get a Jasper, and apparently the Halo/Fable Elite bundle systems are NOT Jaspers. You should be caught up now.
I've owned a Zephyr from launch that lasted just over 3 years and died recently. Since it was out of warranty, I decided to just find a deal on a Arcade bundle Jasper, which I eventually got. Like I said, it's still too soon to tell if it's less likely to die, but I can say thing is crazy quiet compared to my old Zephyr, like night and day.
Since I'm looking for a bundle for a gift, I'm STILL wondering what the likelihood is of a Pro bundle being a Jasper, which is why I'm here in this thread.