It's refreshing to see that the press is not just parroting the marketing hype that Skype has sent out for their 5th birthday. FierceVoIP has a good article, as does iTWire.
Besides the frozen video that my partner experienced last weekend, I have had two continuing problems crop up again this week. I have been running Skype on my older laptop with Ubuntu the past week or so, and on Monday (September 8th) it suddenly delivered a chat message to me that had been written on August 25th!!!! There is no doubt that the sender and I had both been online with Skype many, many times during the TWO WEEKS that it took to deliver that message, so obviously the presence reporting / message delivery is still not fixed, and is not unique to the Windows client. Oh, and for those naive few who think that you can "force" a chat message through by clicking the "call" button, regardless of online status, you ware woefully wrong, of course.
As I have had Skype running much more than usual the past week or so, it has also been clear to me that the presence reporting is still as random as ever. I basically get a steady stream of "xxx has gone offline..." / "xxx has appeared online..." messages all day long, and there is no doubt that those people are in fact not doing anything of the sort.
I suspect that this problem, and therefore the chat message delivery problem as well, are being caused by the fact that Skype's "SuperNode" system is vastly overloaded, and that is why it is not limited to just the Windows client, and also why they have been unable to fix it for well over a year now, despite their silly claims that it "should be fixed" with basically every new release. If I am right, you can expect that it will not be fixed anytime in the foreseeable future, and it will probably get worse.