Yet it seemed so cool...

At the time, the Newton seemed like such an incredible device. As noted, however, the poor handwriting feature which was it's hallmark, doomed its success. Plus now it seems so big to handle!

Trademark protection

You need to be selling something in the trade to retain a Trademark, so that's probably why Apple didn't bother to renew. For a company the size of Apple, the cost of a renewal is trivial.

If I'd been Apple's lawyers or marketing, however, I'd have found either an app or a series of minor products to attach the name. For instance, they turn their digital video adapters into a family of Newton adapters, complete with that light-bulb logo on each. That'd also distinguish their adapters from the knockoff companies.

Newton is a great name even if the original product came up a bit short. I wouldn't let it slip away so easily.

Still got mine

The handwriting recognition was fairly good in models after the MP120. I still have my MP130 and MP2000, both fully functional.

I don't have a Newton anymore to directly compare, but on the rare occasions I see someone manhandling one of those "phablet" phones I am reminded that Apple has been there, done that, and had better handwriting recognition then than Samsung has now. :)