It seems quite likely they wouldn't undercut the Galaxy S really, for something that has much more feature wise.

Which is a shame. Though, if I can get one with only a data plan (I am not Dom Jolly) for £100, with a decent data plan... preferably 18 months (ha) it'd be a no brainer for me.

It's basically a large Galaxy S, and that in 8GB trim sells SIM free for around $500. Chances of Samsung selling it below $600 unsubsidised are slim to non-existent.