Not really as you have a lot more options

If Vodaphone never charge me other than sending anoying text then i dont care.

If they do charge me then;


- you will ahve a £300-£400 handset you can sell. Then get a new contract and a new phone.
- you may really like the N900 and want to keep it for the length of you new contract. In this case you have an even more expensive phone that you can seell
- you may want the N900 to play about with, see what Meego is like but keep your new Phone as a main phone.

All of the above will be subject to a Gig hard cap. So what, if you are gonna be charged for going over a 500mg FUP anyway, this is a win win situation in my eyes