I'm working on the principle that by the time the maemo 6 device arrives (December 2010? January 2011?) my poor n900 will be quite worn out. I make him work extremely hard, and he'll be ready for the 'rest' that comes with being my secondary device. Added to which, by then maybe I'll know enough and have grown up enough to be brave about command lines, Xterminal etc. Heck, I might even know how to write a line of code by then!

There are two questions to ask: will this device do what I want right now (along with 'does my current device do what I want, so I can avoid changing). Secondly, will I break my heart at having a device that does a high proportion of what I want just because there's something Newer out there.

I bought an n95. One of the first in the county - it arrived on the first day of release. A while later, Nokia added 8gb memory, (did they add more arm?) and generally improved the hardware. But my old, first generation n95 still did what I wanted, so I didn't fret.

The questions you need to ask are partly about the device (what will it do) but also about yourself (what do I want, feel, and care about). If having the newest, shiniest thing on the market matters, even installing maemo6 on an n900 won't cut it as the next device with have wizzier hardware. In the end, you need to answer your own questions.