I've got to agree with GeneralAntilles here, Nokia's approach to the tablets has been VERY restrained compared to their phone releases.

Nokia launch about 30 or 40 phone models a year including many smartphones, so even if you buy the latest Nokia phone you can bet that a newer model will be out within a week or two. This is what all phone makers do, it seems to be what the market wants, and if the iPhone takes off (ie. if it sells significantly more than the 0.5% market share it currently has) then Apple will be bringing out several models a year as well. The phone market is so fast moving because it sells more than all other electronic gadgets put together, so the time to recoup development costs on a particular model is much much shorter.

Nokia's tablets by comparison have had three models in two and a half years. This is very slow going by Nokia's standards, I don't think they're driving people into buying new devices at all.

If they wanted to force people into buying the latest tablet, they certainly wouldn't have issued OS 2008 for the N800 just as they were launching the N810, or bothered releasing Hacker Edition OS 2007 for the 770.