Try and establish whether there is a reason for it if you don't like it and if there doesn't seem to be a reason for it then talk to her about it...?
If there is a reason for it then talk about that reason, if you don't like it, tactfully talk to her about it. Don't say something like "you're being really needy lately what do you want?" (sure-fire way to get dumped quicker than you can say "But I..."!!!), word it carefully so it creates conversation and discussion rather than confrontation.
For me personally I was with a girl who had lowered self-esteem... and that made her clingy and needy. And I didn't like that. I can't stomach the "but you're all that I have" and the whole concept of being the centre of a person's world. Just weirds me out. But that's me... I know it sounds really horrible but I don't like that kinda stuff.
So I guess it just depends. Find out if there's a reason for it before you react/over-react to her needyness (particularly whether it's something that's come on quite suddenly).
You should definitely not ignore it, otherwise your relationship will deteriorate. I reckon most men would find this difficult to deal with. I was like this in my first relationship and he hated it. Eventually he couldn't cope with the pressure of living up to this idolisation I held for him. He told me when we broke up that he didn't feel like he could make me happy. I definitely relied on him too much - it taught me a lot about how relationships should work in future.