I got the following analysis from a comment @ rediff. Thanks for the guy. Its a nice one.
Krishna avatar - Vincent Poovaraghavan Lord krishna is actually a dalit, he is dark-skinned [shyamalam]. He saved draupadi when she was being violated and he was the actual diplomat in mahabharatham. Lord krishna dies of an arrow striking his lower leg. Now look at how vincent was introduced.. he appears when asin is about to be molested and he saves her like draupadi. Vincent is the dalit diplomat, fights for land issue [soil issue to be exact] and dies from the metal rod striking his leg. Oh even five of vincent’s men are drugged at P. Vasu’s.. sounds familiar???
Balarama avatar - Balarama naidu This is an easy given. as the name suggests and the role personifies you can easily get it.
Mathsya avatar - Ranagaraja nambi nambi is thrown into water in an act of trying to save lord from being thrown into sea, though vainly. what more clue do you want?
Varaha avatar - Krishnaveni paatti During the mukunda song, krishnaveni paatti does varaha avatar in the shadow puppetry. The frame freezes on it for a second. there is the clue. Moreover, in varaha avatar lord actually hides earth so as to protect life forms. Here too krishnaveni hides the germs - life form inside the statue so as to protect.
Vamana avatar - Kalifulla khan remember in vamana avatar, lord vishnu takes the vishvaroopa, that is the giant form! Hence the giant kalifulla here symbolises vamana avatar.
Parasurama avatar - Christian Fletcher Parasurama is actually on an angry killing spree and killed 21 generations of the particular kshatriya vamsa. Hence the real KILLER… Guess what thats what our Fletcher is! He comes around with the gun [modern upgrade for axe] and kills everyone around. I have to check if he kills 21 people though.
Narasimha avatar - Shingen Narahashi first of all the name itself is a play on the words singam [means lion in tamil] and narasimha [the avatar being symbolised]. Lord Narasimha manifests himelf to kill the bad guy and he also teaches prahaladha. In the movie, he shows up to kill the killer fletcher! and is also a teacher.. Lord Narasimha had to kill the asura with bare hands and hence the martial arts exponent here.. get it?
Rama avatar - Avatar Singh Lord Rama stands for the one man one woman maxim, kind of symbolising true love.. Here Avatar portrays that spirit by saying that he loves his woman more than anything and wants to live for her.
Kalki avatar - Govindaraj Ramasamy As you know, the hero in kaliyug can be none other than the Kalki avatar!!!
Koorma avatar - Bush This is the most loose adaptation I couldn’t clearly comprehend. But if you look at the real koorma avatar, the lord is the turtle/tortoise that helps in stirring the ksheera sagara and bringing out the amruth. This essentially creates war among the devas and asuras. Similarly today Bush facilitates war between you know whom… May be Kamal also indicates that.