Well... Heikki is no Fernando Alonso now is he... and Lewis pretty much had Fernando pipped at every post through out the whole of last season. However I do believe that Heikki will beat Lewis at some point during this season. Heikki deserves alot more credit then he gets sometimes. At the Race Of Champions he has brilliant.
I'm not certain I follow your logic. You say Kovalainen is 'no Fernando Alonso' and that he will beat Hamilton at some stage throughout the season, which suggests that overall Hamilton will have him in his back pocket. After all that, you say Kovalainen doesn't get the credit he deserves.

Kovalainen has shown he is a good driver. He took a few months to get used to things, which some people need, and I'm surprised that he has not been mentioned that the Renault is an awful car to drive, even in 2005 and 2006. They're decent but require a certain kind of driving style. After this period of adjustment, he well and truly destroyed Fisichella. Although one must be careful when looking at testing times, Kovalainen has buy and large been faster than Hamilton, which would again suggest Kovalainen is more than a match for Hamilton.
Let's also put Hamilton in perspective. He's been trained up by McLaren basically from when he was out of the pram, and has been parachuted into one of the best teams and had one of the best, if not the best, car on the grid. Yes, he did very, very well, but it's also worth noting that I would expect most drivers to do that given the equipment and service on offer.

Ayrton Senna: WDC 1988,
1989, 1990, 1991
McLaren: WCC 1974, 1984, 1985, 1988, 1989, 1990, 1991, 1998,
1999, 2007McLaren: WDC 1974, 1976, 1984, 1985, 1986, 1988, 1989, 1990, 1991, 1998, 1999, 2008