It doesn't really matter right now but in the future it opens doors for peripherals, such as high fidelity wireless surround headphones for one or perhaps a XB1 centric tablet that transmits video directly from the console. Of course USB solutions exist so maybe it won't make a big deal, but I like that the option is there. Perhaps you are right about the long term impact.
By the way...its 3 mb/s, not 3 MB/s. That's equal to 0.375 MB/s versus the 31.25 MB/s that the XB1 can do. Quantitatively, that is a big offset in the XB1's favor if MS can come up with some cool ways to take advantage of it. 🙂