Which BB10 apps? There are already many shown if you run App World on your Dev Alpha.
If you mean ones that are submitted *only* for the BB10 phones, and not for the Dev Alpha, then I'd imagine you will never see those on the Dev Alpha and won't see the apps at all until launch, unless you're one of RIM's internal testers or carrier partners.
When adding a file bundle, you should select Platform=QNX, Min. OS=10.0.0, and then selected Device Support. In the dialog, you'll see BlackBerry 10 listed. You can pick All, and get both BB10 phones and Dev Alpha, or select Show Devices and pick individual ones.