iTunes Plus is now available also in the Finnish Store. They've also dropped the price so you no longer have to pay a premium for DRM-free, 256kbit/s M4A-s which is great.
Upgrading your existing purchases isn't free however and costs about 3 EUR on average per album (25% of the album price). :( The system will not suggest upgrading your existing copy when you try to buy a Plus version of something you already own (which is what prompted me to find more about this). It's also not possible to upgrade individual songs or videos. People should really read the FAQ on iTunes Plus. :)
12.99 EUR is roughly what you would have paid for the physical CD so we'll see how well this service sells. Being curious, as well as a total sucker for iTS's instant gratification, I decided to try it out.
Anyways, I hope this service will fly and that we'll never have to face DRM again (although I must say Apple's implementation has been quite user firendly). While I'm not sure how many customers will decide to pay an extra 25% for stuff they already own, I can't see why people wouldn't want to opt for the Plus version, for the same price. OK, it takes up twice as much space on your iPod, but I'm pretty sure most consumers will not even think about that and they can freely down-convert it if they want.
Currently only a subset of content is available as Plus (e.g. 4 out of the 63 albums I have bought from iTS), but as the selection increases, I think the Plus moniker should just fade away and M4P content should be called “iTunes Minus” instead. ;)