Launch titles move hardware......In Japan. In the US? Not so much. It's been a real long time since a system stopped selling out quick in the US. Dreamcast, Xbox and GC were the last 3 systems to stop selling out within 4 month of sale. This gen, the X360 sold out for about 5mo, Wii for 9mo, and PS3 for about 3mo. Now, with those systems, any issues of failing to sell out (ie PS3) was due to price, not titles.
What matters far more than launch titles (atleast from what I've seen) is the software made from the 3-6mo post-launch period. Games in those areas can really make or break a system in the US. In the US for N64, we had only a handful of titles, but they were very well recieved (like Turok), but managed to break the system versus the much better-titles of PS1.
Launch titles help, but if there's no quick followup, the system sales will fold quickly. IMO, titles like GRAW1, Oblivion, Mario Party, Super Paper Mario, Motorstorm, and such were very important for their respective systems as they helped continue (or not really help) sales after they sold out.
Back from the dead, I'm afraid.
