I donot agery that ps2 sony will stop producing ps2 games. Sony cannot ignore their coustomers. Yes ps3 will be a good console.But it will take time for ps3 to get into the homes. take a look at Xbox, many game companies are still releasing games for xbox even after xbox 360 has been released .So my guess is that they will keep releasing games for both ps2 and ps3 simultaniously till ps3 gets hold on the market. then slowly the will decrease the games released for ps2.
Take a look at my example.
Take for example the transition from 32 bit processor to 64 bit processor. If software companies like (M$) said they from now onwards our software will run only on 64 bit machines and asked us to buy only 64 bit comps how will you feel?? the same way even you might not go for a 64 bit system immediately but maybe after a year .
so how do companies tackle this problem?? they release two different softwares i.e., one for 32bit and one for 64 bit. so both the company and costumer are happy

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Charan