Many people liked them, and its effectiveness was shown when the average rating would sometimes be different than the normal review.
And it lets people express their views on the game more.

When will they appear again?

I wish to have them back too. If you look at your public profile(click your username under your avatar here in the forums), you'll see "My Games" and under it, it says "Coming Soon". Just a matter of time Ferret.

I agree with this. I loved the old rating system with the stars. I hope it comes back.

They said they're working on it.

It is a nice feature, but is it really that important? In most cases, the person who rates a game is going to be someone who bought the game AND in most cases they'll only have bought the game because they loved the game or had fond memories of it. So, most of the time the user rating should be fairly high and not necessarily an accurate indicator for people to judge games by.
So saying, if they bring it back, I'll rate my games again, and give SMRPG a lowish score and last ninja 3 rock bottom

I don't think that's true. Probably almost half the games I bought are games I hadn't known about, especially on consoles I didn't own like the Turbo Graphx. Also, sometimes you download a game you used to love and realize your nostalgia-tinted glasses have been fogged over. How on earth did I ever think the second Toe Jam & Earl was fun?
Plus, you can always rate games you've played before but didn't download yourself. I've played SMRPG but am not going to download it, and while I wouldn't give it a lowish score, it wouldn't be highish either.

It's on the to-do list to bring back again, this time bigger and better than ever. Watch this space!

But some people have hugely different views on some games.

OoT is defienetly a great game, but to many people it is overrated.
Personally to me, Kirby 64 should not have gotten a 5, as it is one of the best of the Kirby games and a great platformer IMO.

A WiiWare example is Gradius Rebirth game, which the reviewer said that he did not like horizontal shooters.

Again, there are many different views, and for a few games, the main review will have lots of seperate argument.

I'd like to see user ratings, it's nice to see the communities feedback on the game as well.

So... is it going to appear again?

Yep yep, it's coming

Well for one, it would remove complaints about review scores since they could make their own ratings.

Bit Boy got a lot of mixed reactions for example.