Anecdotally, I recently bought one of Microsoft's new bluetooth mice, and it stopped functioning correctly after 3 weeks.
I'm still using the Microsoft natural keyboard and optical mouse I purchased in ... 2001? The sidewinder joysticks were always excellent. My original XBox is going strong; the Duke being perhaps the best designed and built gaming controller to date. The 360 controllers are similarly excellent (though I miss the Duke's size). The wireless notebook mouse I bought 2 years ago is the best wireless mouse I've used, period.
I can't speak to the Zune, having never owned one.
I assumed that with that track record, the accusation that "the 360's reliability problems were known but allowed to slide in blind pursuit of launching first" made the most sense. It was deeply disappointing, but I do give the hardware group itself the benefit of the doubt.
I'm wondering if Microsoft will have a leg to stand on arguing that consumer demand for environmentally friendly products negates their claim for defective electronics as high-density electronics are hard to solder efficiently using non-lead based solders. If they can get a judge to side with them that the consumer demand for 'green' products means a higher defect rate could get the entire class action kicked out, but then the 360 wasn't exactly advertised as environmentally friendly (like MacBooks are) so if this would fool a judge or not is a wonder.
The current 'jasper' model 360's have a RRoD rate of less than 4% which is actually significantly better than the industry standard of 5-8% for hardware failures in the first year.
Sure, if we ignore everything but the Xbox, Xbox 360, Zune and Zune HD their record looks far worse.
But is that a fair bucket to build?
Well, to some extent, it is. A mouse or keyboard is one thing, a console or tablet is another.