So what, we're using 128-bit
Unless I'm mistaken the default WEP key size is 128-bit and of course every bit doubles the number of possibilities.
Let's assume for just a second that the attack is scalable and the time taken simply doubles when the number of possibilities doubles.
Starting with the premise of 1 minute for 104-bit and the fact there are 24-bits remaining between the 104-bit demonstration and the 128-bit reality that means we should double the 1 minute attack time 24 times.
This gives us a result of 8,388,608 minutes or 139,810 hours or 5825 days or nearly 16 years.
I wouldn't say 128-bit WEP is dead just yet although obviously improved attack mechanisms and faster CPU's will no doubt continue to erode it.