@Italo: Hi there - with all due respect, IMHO I think it's still much, much too early to say things like Lewis is "very close to these great drivers".
LH is on the cusp of winning his 1st WDC, something which, going into the last couple of races last year, was 'his to lose' in his rookie season. BUT he crumbled under pressure making mistakes that left us open-mouthed in disbelief.
This year, I think he has matured somewhat so that he can handle the pressure a fair bit better so I am not expecting him to fluff his chances this time round. Don't get me wrong - he richly deserves where he is right now since he has performed well this season. I think his error-free performance in Shanghai showed that he has learnt to get the job done - it doesn't have to be a 'flashy' win - sometimes just collecting the points is all that matters. He would become a laughing-stock if he were to lose the title race this season as well from where he is placed right now. And I don't think he could bear it. But, like I said, I think it's unlikely he will fail again.
Anyhow, I think there is a danger of confusing two distinct things here. First, there is his 'potential' and second, there is his 'greatness'.
Potential: LH has huge potential. Of that, I have no doubt. But he still has a lot to learn. Not so much about the technical side of things or the driving itself. He has learnt those over the past 2 years in F1 and the many years it took him to reach where he is today. No, I mean he has to grow as a person. He has to mature as an adult, toughen up as a professional... He needs to be more self-controlled so that he irons out all careless mistakes. He needs to be thinking more tactically about what risks to take, which risks to spurn. He drives with his intuition at the moment. IMHO he needs to drive with his head too.
In recent times, the driver who epitomised this the most was Alonso when he beat Michael Schumacher to the title in 2006. He simply didn't put a foot wrong. That is what personnifies a 'consummate professional' who is completely in control of his game. Alonso soaked up the pressure that year and was unflappable, single-minded, undistracted.
Since then, we have seen a more erratic Alonso in 2007 and 2008 since (1) he has been partly distracted in 2007 by the way he could not mentally and emotionally adjust to the fact that his rookie team-mate was one of his closest rivals, and (2) he has spent most of 2008 in a lacklustre car and Renault has only really narrowed the performance gap in the last few races of 2008.
Greatness: many drivers have great potential yet do not win a WDC. So, by winning the title even once, LH is achieving something truly special. It's like a dream come true.
But many drivers have won the title once or twice and then not gone on from there. Look at Kimi. He has had so many seasons where he nearly won or was dreadfully unlucky race after race (with engine reliability) and that ruined his title chances. Finally he won the title in 2007 and now he seems flat. No fizz. Kimi's main achievement in 2008 has been to drive the most number of fastest laps in the races themselves. But winning is not just about some blisteringly quick laps here and there. It is about performing consistently. He hasn't done that in 2008. Hopefully, Kimi will find his way again next season.
Other one-hit-wonders include Jacques Villeneuve, Damon Hill, Nigel Mansell.
But the true measure of greatness is to excel over one's peers for a significant period of time AND in the process to transcend the normal mundane standards of the sport.
I must confess, I have watched F1 since my early teenage years. As a result, I have not seen the old greats from the 1950s and 1960s. I was lucky to see the classic duel between Ayrton Senna and Alain Prost. And we have all witnessed the dominance of Michael Schumacher.
Those drivers were titans who were head and shoulders above the rest of the field. They were not just drivers turning up to one race after another just earning a living hanging on to their place on the grid for as long as possible. No. They captivated us, mesmerised us with their exploits and they truly transcended the sport of F1. Giants like that are extremely rare. I wonder when we will see someone like that again. After winning the WDC twice, Alonso had the world at his feet. He had announced a year in advance that he would be leaving Renault for McLaren. How he must wish that he had moved to Ferrari instead! I have no doubt that Alonso would have won in 2007 and 2008 if he had been with Ferrari. Instead, Ferrari has now seen the less attractive side of Alonso in 2007 and that has put Luca di Montezemolo off signing Alonso. Hence LDM said he preferred Massa to stay instead of pairing Kimi with Alonso. That could have been a combustible mix.
What of LH? If he wins the WDC again and again, it will be because he has filled the deficiencies I have mentioned above. But till then, talk of him being close to the greats is simply premature IMHO.
The great thing is that there are talented drivers like Kubica and Vettel who could go on to achieve great things. So there is hope for the future...
Just my 2 cents