@ johnsobas
I thought it was obvious, but read above.
No, currently the PS3 has no game with an attach rate similar to Halo 3.
No, there are more multi-platform games than exclusives. The PS3 bestseller list has more multi-platform games and lack exclusives like Lair, FolkLore or my personal favourite Super Stardust HD.
No, they are unsurprisingly losing money on the hardware (very high specs vs cheap price). Overall not on software.
You will have to take install base ratios into account for when those games launched.
Not rare, but more multi-platform games in comparison, but its likely many more full PS3 exclusives will be released during its lifecycle because Sony itself has more software development muscle. Considering 360/PS3 owners on average buy less than 5 games a year, you will see well more than that amount of exclusives per year.