@rwmj - the question is not whether it is obvious now but rather was their invention obvious then. Do you have any reason to believe it was obvious then? Remember that this very question has been litigated with MS doing everything in their power to demonstrate it was indeed obvious then, that there was prior art, and they failed! So it is easy to allege something like this now but I suspect that you are suffering from the hindsight effect and don't actually have any evidence supporting your claim of obviousness. I don't doubt your sincerity and I don't mean to be rude, I just don't think you are likely to have done the research (as MS and their attorneys did!) to prove it was obvious THEN.
The obviousness test is basically off the table after the patent has been granted. This is one of the things that is problematic with the system. Patent examiners tend to be too lenient, but the end result is you now hold a patent that is very difficult to overturn.
IMHO you are missing an absolutely critical point and are therefore falling prey to the hindsight effect.
Let's imagine that you have a brilliant idea right now, one that NOW is not at all obvious. What does that mean? It means that NOW (a) there is no prior art (b) there may well be teaching away from the art, in other words, even though the field is a familiar one and you would think it obvious once pointed out, nonetheless there is no evidence that anyone has thought of it before (c) there is no public domain publication or record of a talk etc .... Such evidence is taken as evidence that it is not obvious. Now let's assume that you take your idea further and turn it from an idea - an insight if you will - into an invention. That may involve a great deal of time and money. In some cases it certainly does. Now let us assume that you release a product and it achieves great success. The very success of your product means that it will become a part of popular culture and there have been several studies that show that within a remarkably short period of time people take what was your innovation for granted and consider it obvious. Bear in mind however that it wasn't obvious when you thought of it and when its obviousness was considered, for example, by the patent office. Failure to recognize this and the associated hindsight effect leads to people making statements about how obvious something is when that is completely irrelevant. The question is not how obvious it is but how obvious it was. If a patent is granted it can always be challenged and invalidated if someone is able to demonstrate that there was indeed prior art. The patent is assumed to have validity but that does not mean that evidence of prior art will just be disregarded, it just means that the evidence has to be clear.
