"Will DS hit 100m in its lifetime?"
Thats a big question that has multiple answers. It really just depends on how you phrase the question. Will THIS DS + DSLite hit 100m? Possibly. It'll get close to 90-95, if not more, within the next 2-3 years. The big question is how long nintendo decides to keep the DS.
I know I use the same argument as the Wii, but I just wonder if/when Sony will launch the PSP2 (before a new DS, imo), and if/when Nintendo responds to it.
Provided Nintendo keeps the DS family going...The DS family will easily beat out the Gameboy family (GB, GBC, GBA)'s lifetime sales by a mile, and could get close to rivaling the Playstation family of consoles.
Right now we got:
Playstation Family: 235m units (105m for PS1, 128m for PS2, 5m for PS3)
Gameboy Family: 199m units (via Wikipedia for GB, GBC, GBA, GBASP, GBM)
Nintendo Entertainment System Family: 109m (via wikipedia for NES and SNES)
Double-Screen Family: 40m (DS + DSLite)
Xbox Family: 35m (Xbox + Xbox 360)
The DS family, provided it gets atleast 1 more revision before Nintendo switches to a new system, should pass the Gameboy family. If Nintendo keeps the DS family for 15 years (another 14.5 years), then it should become, by a small margin, the largest family of gaming systems at around 400 million units sold.
Back from the dead, I'm afraid.