If history teaches us anything it's that the first round of hardware from just about every console launch is destined for difficulties.
In the case of the original Playstation there were heat related issues, disc copy protection issues that caused failure reading discs (a lot more than Sony ever cared to admit to) and other problems that made the Playstation work less perfectly than it was supposed to. I remember a lot of those problems as I had one of those "release day" boxes. While it never went in for repair, it definitely never quite worked perfectly. Some games would skip at the worst possible places failing to successfully load and causing returns for other copies of the same game that would just so happen to fail in the exact same spots.
Over time, as with most of these systems, the original Playstation hardware was revised, improved, and fixed so that purchasers of the later versions got systems that worked in almost all cases. Note you can't say all because there were changes that got made along the way that wound up breaking some of the very early games which had been written on hardware that included the original bugs that were fixed in later bios revisions and such.
The original Xbox had similar problems, and later (of course) the Xbox 360 came along to far more problems. Besides being in very short supply (as has been the case with the PS3), the original series and even many of the later series of Xbox 360 systems have found return trips back to McAllen Texas where Microsoft winds up taking the bad boxes and shipping out (hopefully) good refurbished ones to the customers that have experienced difficulty.
Microsoft obviously found some design and engineering flaws in their systems as they wound up having to extend the original warranty period on their first generation of the 360 hardware (systems manufactured before 01/06) and even today seems to be hitting more than a few problem systems with "birth dates" in the 06 year.
Don't get me wrong here, I give credit to Microsoft for stepping up (even if they were dragged to it) to the plate to offer warranty service and repair/replacement of the bad hardware but it comes back to issues in engineering and perhaps quality control that come up with each new system that is rushed to the market.
Microsoft also had issues (and continues to) with not being able to make the Xbox 360 run the entire suite of original Xbox software (games library). In Microsoft's case it was intentional as they had to go with an emulation system and each game seems to require new modules for the emulation system. Rather than using a lot of time to make the 360 run all of the original Xbox games, Microsoft choose to make sure that the system would run the most popular games and has slowly dribbled out updates to the backwards compability list over time. There are still literally hundreds of games (if not over a thousand) that don't work on the 360 that worked on the first Xbox game console which is why many gamers were forced to keep both the old system and the new if they wanted to play all of their favorites.
Sony has had to fess up that their Playstation 3 (PS3) will also be hindered with incompability issues when it comes to old software. They shot for 100% compatibility on their old library of games, but they missed that mark. Sony deserves a lot of credit for trying to maintain the ability to run the old games as this is the second time that they've been down the path of backwards compatibility. Sony delivered (for the most part) when they went from the original Playstation to Playstation 2 (PS2) hardware.
I'm also told (by folks in the gamer stores) that something that PS3 owners should be prepared for is the added jump in the electric costs that they'll be facing just for powering the thing up. As a friend (who happens to be flipping the system via eBay sale) mentioned when asked about the apparent high costs of shipping stated in his eBay ad the thing is heavy. The game store geeks mentioned that in discussions I heard the other day, along with mentioning that for most people the PS3 hardware will be the single biggest power drain in their home. The high number of processors in the system plus the hard drive and Blu-ray drive (and the fans to help keep all of the above cool) suck up the juice. Mr. Burns (the Simpsons) would be proud
There are other obvious things that the PS3 owners will also be able to look forward to and take advantage of, including Blu-ray discs, the new series of games that are out or will come out for the system, and the new peripherals too. In the case of the games and the peripherals though, the costs for all of the above will be higher than they were for the older generation of games and accessories. Like with the Xbox 360, the game developers will invariably charge higher prices for the next generation games. For at least the first several months of games, many of the games will be only marginally better than the same games for the older generation systems.
On the 360, system owners found that instead of paying $39 - $49 for games, they were asked to pay $59 and $69 for basically the same games. In some cases they were asked to pay those higher prices for games that had less features than the same titles for the older hardware (Madden 06 as a big example, along with several other EA titles that proved frustrating for the lack of feature set and the higher prices).
I hope that those lucky enough to own a Playstation 3 enjoy their new toys and the games that will be available for them. I expect over time when we look back on the early adopters that several of the issues I've mentioned here will show through.