Baghdatis wasn't just someone who managed to go to AO final and made Federer afraid of losing the final (as Federer admitted) but he beat many top seeded players to get there and with style. Commentators were thrilled and retired pros were talking about a phenomenon in every way let alone the newspapers, media and fans everywhere. His girlfriend was awsome and also tennis world needed something new to talk about and feel refreshed.
So he has his own page on ATP site whereas Nalbandian doesn't because he has nothing special apart from his game and the same holds for Ljuba and Davydenko for example.
Baghdatis splitted the tennis fans into two (lovers and haters), Nalbandian, Ljuba and Davydenko didn't and to do that you need to make a difference and be well known.