I don't know if the community actually has/had the opportunity to do all the required changes to the N900 even if they wanted to. For example, until PR1.2 which came out in Spring 2010, I couldn't even reload the credit on my phone's SIM because the N900's phone application (or modem stack) didn't bother to implement the required USSD support. The only thing the community *could* do was what it did: release a crappy homescreen applet that might or might not work. (I just swapped my SIM card into my old 20€ cellphone for which the N900 was a replacement...) Couldn't actually change the phone/modem software, because there's no source for it to edit. At least that's how I understood it, and which I found to be quite pathetic. (Which I think is such a shame, it could've been such a nice platform, and it mostly, but not quite, is too)

Implementing AES directly in the chip makes implementing AES in userspace also less vulnerable to cache-based side-channel attacks against AES. Also note that there has been work to use these AES instructions in implementing (some of the) candidates of SHA-3 (http://crypto.rd.francetelecom.com/sha3/AES/)

Actually, you can apparently use larger Mersenne Primes to improve results in totally different but very useful fields, like privacy-related schemes. For example, this paper http://eccc.hpi-web.de/eccc-reports/2006/TR06-127/index.html uses large Mersenne primes to get interesting results on Locally Decodable Codes and Private Information Retrieval Schemes...