i can answer this for you...
Typically when a product first comes out, it has what best buy terms as "devo" status (devoid of operation). What this means that in the event the item is returned, broken, defective, etc...they send it back to the manufacturer for a full/partial refund. After the product has been available long enough to prove viable, the status is changed to repairable (not sure if bby corporate decides this, or the product manufacturer, but crap brands like emachine and mintek are devo 99% of the time, whereas other brands go through this cycle. all internal pc components, cd's, software, etc... are devo FYI). A PDA has maybe a 3-4 month retail in store, and as it is new will most likely be DEVO the entire time they sell it. There is no way of knowing exactly when the status will change or if it will, but sadly it doesn't matter because the psp brochure doesn't say anything about an exchange in the event of problems. There are 2 official loopholes within their service plan that can lead to a replacement. One is that when the item is sent to the service repair center, they deem it is more costly to fix then to replace, which i've seen happen several times on PDA's (except for broken buttons/springs/hinges. keep in mind, broken screens are considered misuse and abuse and negate any warranty). If they deem it is more costly to repair then to replace, you'll have the dollar amount you paid for it (assuming you have the receipt, otherwise you will get the lowest selling price the product has EVER had) towards a new one. The 2nd way is using the No Lemon policy. Basically, if the device is repaired 3 times during the warranty's time frame, and has a fourth failure, it's considered a lemon and will be replaced. This of course means you'll be without the device for 4 X repair/shipping/part ordering time (4-6 weeks each). You can opt to buy an open item loaner to tide you over until your device is returned, and then return the open item for a full refund. Of course, any manager has the ability to ignore these rules, as does the lead tech.
The only products i ever buy warranties on are cd burners, car speakers, vacuums, large appliances and big screens can be good at times, cell phone/laptops (only due to battery replacement if not holding a full charge), most anything that offers a PRP (product replacement plan, basically a one time exchange guarantee based on the paid price), printers can be a good thing (since color/black ink cost the same as a new printer anyhow) and i think they just started offering them on hard drives which would also work for instant grat. And in case you're wondering, i've worked there as a tech. Yes i think it's a BS system, they don't even keep records of the purchase price if you buy a warranty, and that's assuming your info was saved in their database when you purchased the warranty (KEEP your receipt). 1 out of 10 service plans will ever be used, so you do the math. I can't begin to count how many items i've seen "serviced" that come back to the customer with the same problem or another one altogether. I've seen a legacy PC go to service for not booting, and they replaced EVERY single component which (not even counting man hours) cost double the purchase price.
I'll end this here, but if anyone has any specific questions i'll be happy to answer them to the best of my ability.