Wii - 7 year life cycle - minimum 60 million
the pace right now will push Wii past 10 million sometime during August. that's 10 million units in 10 months. end of year will see Nintendo's big 3 which i estimate will push sales around 15 million at end of year (the biggest pusher of those being Mario Galaxy). such a fast growth in user base will be very attractive to publishers. good 3rd party support and Nintendo titles will have Wii selling at a steady pace in 08 and possibly continue in the years to follow. i gave a minimum of 40 million but i think the momentum it has is just the beginning of life cycle that will end in sales around that of the PS2 if not exceeding it.
Xbox360 - 8 year life cycle - minimum 35 million
while it is faring better than the original Xbox, the X360 will be passed by the Wii by the end of the year. Wii will take a majority of 3rd party support for titles appealing to casual players leaving X360 with titles only appealing to gamers. even if MS decide to start having more casual targeted titles (either by through 1st/2nd party development or paying 3rd party publishers), X360 is still going to appeal more to gamers and will be fighting PS3 for the developer support of the gamer targeted titles. overall X360 should fare better than the original Xbox but without the mass market support it will only sell double that of it's predecessor. still good but nowhere enough to completely counter the billions of dollars that's been lost on the Xbox franchise.
PS3 - 8 year life cycle - minimum 50 million
although X360 has a slightly decent lead of 7 million, PS3 is likely to catch up soon enough. why? firstly Final Fantasy XIII, Metal Gear Sold 4 and Gran Trousimo 5 are going to sell alot of systems. secondly, it will have consumer support in all 3 major territories. even though Japan will be in Wii and DS frenzy, PS3 will still do well in the region. in Europe PS3 will at least match X360. in North America, if it doesnt catch up to X360 it still wont be far behind. good sales in all 3 regions will mean a healthy amount of developer support. combine that with Sony's increase of in house development and PS3 will have an attractive library for gamers. it will also have expanded audience software but for a long time the price will deter alot of casuals. late in its life they may pick it up but it will likely be too late. not all too likely that it will reach final PS2 sales.
summary
PS3 and X360 will battle it out for HD console of choice. however larger 1st party library and a few more popular 3rd party exclusives will have PS3 push ahead of X360. mean while Wii will be picked up by alot of gamers as a second option (due to some interesting exclusives) and by casuals because it's becoming this generations casual consumer's console through pricing, fun interactive controls and expanded audience software support.
my final sales expectations
Wii - 140 million
PS3 - 70 million
Xbox360 - 40 million
edit: note - i didnt take into account what Blu-Ray will do for PS3 sales because i dont know much about the subject. i imagine if Blu-Ray turns out to be the more favourable HD medium and PS3 prices come down, it may result in alot more PS3 sales for Blu-ray alone. that is if digital distribution isnt yet popular by that time.
