England is a country that is, on a global scale, quite good at a lot of sports. In fact if you look at English/ British sport across the board we're up there with the best, especially compared to population size.
However we tend not to specialise. Brazil will always have a great football team. New Zealand will always have a great rugby team. And Australia will always have a great cricket team. For most countries around the world, the best they can hope for is having great sides maybe only for a 5 year period in every 20.
England were the world's best side (regardless of rankings) for at least 2 years before the 2003 win. We were unlucky not to get more 6N grand slams, but as Eddie Butler (for once) put it so well this week: the six nations is a tournament where good teams lose because they are dragged down to a lower level by their opponents. But we consistently beat the SH sides, and also on their own turf. That is a rarity. For that to happen again, we need some serious star players and a period of consistent achievement to inspire a sense of invincibility. At the moment, we have neither... just a lot of very talented players we haven't worked out what to do with yet.
Now, England at rugby are consistently solid... at least in my memory we don't usually get rolled over by everyone; and even at this low point we're at now I'd expect us to compete in the 6N, considering there's only one good side in it at the moment. In the future, we potentially can be a good side, or we can continue like we are. In a best case scenario, players like Rees, Care and Cipriani will all develop into world stars and maybe a few other players too, and they'll pull the rest of the team up with them.
If they don't, I envisage another 5 years at least of mediocrity, maybe we'll grab a 6N ***le or two by getting it right at the right time, and maybe we'll beat Australia once or twice, but it takes a lot more to replicate that 2003. The most important thing is that we don't get like the Welsh and judge every present team next to past glories. It got them nowhere, and it won't get us anywhere either.