How many years have people been predicting the demise of Apple? Get over it.
Eh, well Steve is sick, he IS the company, and he has not groomed a replacement. So, once he goes, its a good bet that Apple will take a significant downturn 2-5 years afterward.
Back to the main question. Lets see how computers have influenced my gaming over the past 25 or so years...
25 years ago I used a computer to generate characters. I wrote a program from my Commodore 64 that had ALL the 1e races and classes, thats everything from UA and all the Dragon mags. There were probably 30+ classes and a bunch of races. It could only do 1st level characters, but I never had the need for anything higher, because we always started out at 1st level.
Now...
I have access to character generators (some good some bad, I have NOT tried DDI), mapping programs, html linked SRD, PDFS, and lets not forget the internet and the hive mind for prepping a game.
Personnally I have not used a laptop at the table very much. However, if/when I do DM another game I plan on using one for at least reference.
The biggest influence for me has been the internet for prepping, game reviews and previews, and free content. The internet has completly replaced my FLGS. ENWorld and related sites completly fills the void, I probably step foot in a game store once a year now.
So 25 years from now...
1) I think brick and mortar gaming stores will be very rare. The ones that survive will have an internet presence and offer niche and fad merchandise at a reduced rate.
2) Every game group will have at least one laptop using person at the table.
3) Some game groups will have elaborate and large screen setups for battlemaps. I expect virtual battlemaps will be very popular.
4) There will be a much increased presence of computer aides for games. DMGenie already does a lot of this now, this type of stuff will only get better.
I don't think that a single company can provide ALL of the software needs for a game the size of D&D. So, IF WOTC and D&D is to go forward and survive, WOTC will need to figure out how to harness the power of Open Source, individual programmers, and smaller software companies.
If I were WOTC I would write some sort of Framework that anyone could write to that would tie all sorts of little apps together. The Framework should be with a proven technology that is scaleable and doesn't require a subscription to use. If WOTC did this with 4e, I would be all over it even though I have reservations about the way the system plays.