http://en.wikipedia.org/wiki/Fiat_Panda
http://cars.uk.msn.com/reviews/fiat-panda-review-2012-onwards
http://www.worldcarfans.com/111083036141/all-new-2012-fiat-panda-third-generation-revealed-video
http://www.rockinghamcars.co.uk/fiat/new-cars/newfiatpanda
If you are going to count facelifts then there were three versions of the original.
No there isn't, as there was only one 'facelift' in the 90's with a revised grille and that was about it!
Yes - I've seen Fiat refer to the latest model as third generation but pedants will have their say/way/day.
Errrr, don't mix generation and mk's.
3 Generations
4 mk's.
Its as simple as that.
Mk1 and mk2 Panda's look very similar but are completely different cars. The mk3 Panda and 500 share more parts in compatibility than a mk1 and 2 Panda!
Always take what you read in Wiki with a pinch of salt, any mupet can change it, as they have despite me and others correcting it time and time again.