Nintendo's latest portable has topped 5m units through the week to September 17, 2011. The 3DS launched in late February in Japan and late March in the West. The question is 'How does that compare to other recent platforms' globally and regionally?
Compared to other recent systems in an aligned region by region launch, the 3DS has reached 5m units slower than Wii, PSP, PS2 and DS but faster than X360 and PS3. If 3DS were to continue to beat X360 / PS3 long term and remain behind DS, Wii, and PS2 (but not PSP) that would put the device on a pace for 80m - 160m lifetime, although its way way too early to project that far out.