360 is 240k away from 1.5 Million and Ps3 is 5.17 Million away. If Xbox sells every week 5k its 20k per month that means that it will sell 240k in 12 months. And the PS3 can sell about 25k per week at best so that is 100k per month so it can sell 1.2 Million in 12 months (including christmas boost)
In 12 months the Xbox will reach 1.5 Million and the PS3 will reach 6 Million so yes the Xbox will reach 1.5 much faster then the PS3 ten.
If you would ask will Xbox reach 2.25 Million before PS3 reaches 10 Million it could be considered a race but this is so obvious its not even worth asking.