I'm not quite sure if you could find it there before the Viva era has ended ,but in the last days I noticed that there is a map of South America (Brazil?) in the background of this page -> http://coldplay.com/post.php Coincidence?
Might be trivial but I'd really be happy if you guys got a Latin America Tour.
Also while i was reading the liveblog I found this:
"Thanks, as ever. for joining us for the photoblog. It's been ace reading all of your emails. That might be it for the Viva tour, but we've got plenty of exciting things coming up on Coldplay.com over the coming weeks and months (tone of which should be beginning any second now)"
perhaps the things mentioned to happend very soon were the logos that appeared.
I think if they really coming to South America they will be confirming the new leg of the tour soon very soon since they tickets need to be on sale on October or November.