This game looks pretty fun for a spin-off.
And to burst your bubble, I really don't think there'll be any NL/HHd cross-compatibility. The game is releasing in just over a month in Japan, and if there were, I feel like this would've been revealed by now, as it'd work really well for boosting sales, because it'd be a huge marketing opportunity. Not only that, but there are several features in HHD - such as rugs, placing items on half spaces that you can "squeeze" past, and even new furniture items not present in NL - so if they were going to make the two, they'd have to patch NL to be able to have all these, which I highly doubt they're going to do.