Personally I've always found Luke-Han-Leia to be more interesting than the new characters. Though Jacen became an interesting character in the second half of NJO and in LOTF. And I'm liking Ben Skywalker now in FOTJ (didn't like him LOTF though!). If they removed the Big Three my interest would dramatically drop. Luke is the Gandalf/Yoda/Dumbledore of the EU at this point, the fascinating character who is so much cooler than every other character around him.
I wish I could feel the same way. I am enjoying Luke and Ben's relationship in FOTJ. In LOTF, I felt that Luke was held back too much in order to make the main villain a more credible threat. Though I enjoyed Ben's development in LOTF. It was largely his coming out series.
As for Han and Leia, I often find it hard to read their passages. I feel they are often shoehorned into some stories just because they are part of the Big Three. I don't think they need to be at the center of events like Luke does. If the background is good for Lando, I could at least see it being good for Han. Not saying put him in a retirement home, he can have stuff going on, but we don't always have to be following it, it can mentioned from time to time, and he can show up every now and then, but I don't think significant chunks of FOTJ need to be devoted to either Han or Leia. With LOTF, I definitely could understand why, though I feel the writers flubbed really exploring the Solo family's crucible.
Outside of name recognition, nostalgia, I think the novel writers since NJO haven't done a good job of creating interesting characters that can take the reins. The Yuuzhan Vong War took out a good deal of them and there haven't been any replacements. The current well known Jedi like Corran Horn, Kyle Katarn, Kyp Durron, Saba Sebatyne, Kam Solusar, etc. have largely been pushed to the background. And they have been relegated to the benches going on two complete series now. And even some of the well known Jedi are ciphers to me, like Katarn (never played the video games). Kenth Hamner is just now coming into his own. And the few remaining young Jedi haven't gotten much spot light either except for Tahiri and Jaina perhaps, and there is a lot of debate about the nature of the focus on them. Tahiri's character has been put through the wringer, and not always in a good, compelling, character building way (though I think FOTJ is doing better justice for her than LOTF did, though there was a recent revelation in Allies that was just icky where she was concerned.) As for Jaina, her arcs are more plot driven than character driven. LOTF should've been her story as much as Jacen's, but Ben got that time, and to some extent, Jaina is being pushed aside for Ben again in FOTJ. I think that's a mistake.
I think the comic book writers have done a better job creating compelling characters that could carry a series and retain fans, and maybe attract new ones, without having to rely on the big three necessarily. I would hope the novel writers take cues from the comics. I recently finished the novel Crosscurrent, featuring Jedi Jaden Korr and none of the Big Three, and I hope we get more books like that. The potential and characters are mostly already there, they just need to get some attention and development.
