No, you can't play blu ray disc movies on standard dvd, but you can play normal dvd on a blu ray disc player. You'll have to get a blu ray disc drive for your computer. Newer model with windows 7 are coming out with blu ray disc, also Toshiba is joining the rest and producing blu ray disc players. Hope this will help you out.
you wont be able to watch blu-ray discs on anything other than a blu-ray player, however if you do invest in a blu-ray player, you can watch regular dvds on that as well, and they will come out in much better High def. quality.
I work at best buy in the home theater section and i can honestly tell you that buying yourself a blu-ray player will not make a difference unless you have a 1080P tv. If your tv is only 720 then the blu-ray player is useless.