When DC characters make a guest appearance on Smallville, sometimes they work and others...not so much.  When Zatanna appeared in last season's " Hex" episode, we all wondered when she would appear again.  It was announced that she would be appearing again this season.  Kryptonsite has posted some images for the January 29 episode "Warrior" and there she is.  
Here's the synopsis:

METROPOLIS HOSTS A COMIC BOOK CONVENTION — DC COMICS’ CHARACTER ZATANNA RETURNS — Clark (Tom Welling) meets Zatanna (guest star Serinda Swan) at a comic book convention, where she tells him her father charmed a copy of the comic book “Warrior Angel” and it holds magical powers.  A young man named Stephen (guest star Carlo Marks) steals the comic book and develops super powers, transforming himself into Warrior Angel and saving Chloe (Allison Mack) from a horrible accident. Meanwhile, Lois (Erica Durance) becomes jealous of Clark’s relationship with Zatanna.  Allison Mack directed the episode written by Bryan Q. Miller.

Hmm.....the gorgeous Zatanna back in Smallville and Lois dressed as Wonder Woman.....sounds like Tivo time.

Oh, and to answer your question, you will never see Diana, Bruce, or Hal Jordan on Smallivlle.  After the GL movie premieres, you might see a differnt Corp member show up though.

Haha omg its kinda cool!  

Sounds like fun.

I don't watch Smallville. I watched the first few season, but dropped out along the while Lana was a witch.  I am curious about one thing. Has Bruce Wayne ever been in Smallville??

WTF? Can Diana at least appear on Smallville? Why can't she be some strange visitor from Themyscira rebelliously observing Man's World, or something like that?

This is gonna be good. (:
I love Allison Mack.

Lois looks more Xena than Wonder Woman, but who Cares, Zatanna will be there and Pix will be watching.

Very cool!

Lois looks good as Wonder Woman.

Zatanna is HOTTTTTT

 There have been some debate about Zatanna not showing for 'Warrior', but if you want to bring Warrior Angel to life....MAGIC IS THE BEST ANSWER. (But I thought he was BALD and does not have HAIR). Would Warrior Angel help take Chole's pain from Jimmy's death?
Lois in the Wonder Woman costume.....PRICELESS! (HAHAHAHA.....). It's a shame that Smallville has not brought one of the Big Three (other than Superman), into the show....despite some references from the past.

LOL @ Lois! 
  
This episode seems, ok I guess!... I am waiting for the show spin-off of the Justice League! 
 
It may suprise many here on the site, but Zatanna didn't do much for me when she appeared!

why does smallville have the sexiest women

"

Hmm.....the gorgeous Zatanna back in Smallville and Lois dressed as Wonder Woman.....sounds like Tivo time.

Oh, and to answer your question, you will never see Diana, Bruce, or Hal Jordan on Smallivlle.  After the GL movie premieres, you might see a differnt Corp member show up though.

"

" um whos the silver guy "

....Lois in the WW suit? WIN.

Konk! Let me just pick my jaw up off the floor.

Omg Yes! :D

Oh that's really going to upset tons of fans of Smallville and DC! Yeah, I don't believe we will ever see Wonder Woman or Batman in Smallville. We might see Bruce Wayne at some point though. Then again, the show is about over anyway right? She does look great as Zatanna though.

i cant wait i luvvvvvvvvvvvvv zatanna

" @robbiesol said:

"

Hmm.....the gorgeous Zatanna back in Smallville and Lois dressed as Wonder Woman.....sounds like Tivo time.

Oh, and to answer your question, you will never see Diana, Bruce, or Hal Jordan on Smallivlle.  After the GL movie premieres, you might see a differnt Corp member show up though.

"

Like John Stewart or Kyle Rayner? They show hints of a possible Alan Scott appearance through the Absolute Justice episode.  "

Bruce and Diana are loooooooooooong overdue for an appearance in this show.... The retro WW costume is indeed hot....