I found the back and forth between Shepard and Liara to be very organic and funny (in that buddy action comedy sort of way). 
However she really just seemed to be Little Miss Faints-a-lot in ME1. Our Bioware giving this character a personality transplant so we like her in what seems to be a larger role in ME3? Its a little insidious of Bioware in my opinion but hell it is working. That being said Lair of the Shadow Broker is a fantastic piece of content and well worth the Best DLC accolade. 
 
What our your fine folks thoughts on this change (or is all in my head)? 

She was boring in Mass Effect 1 and too whiny in shadow broker.

I still don't like her particularly much.

Wait so that means I'm starting to like that bland-ass character and she hasn't changed?!! <looks into mirror> WHAT HAVE I BECOME!!!? :O 
 
Still Garrus trumps all and it will take a Geth-style personality change for that to be altered

I wouldn't call it a transplanted personality.  
 
If you've read the comic it shows that she's just been changed by the events of the start Mass Effect 2, as in the Normandy blowing up. Like forced to toughen up and whatnot. Her search for Shepard takes her to Omega, and you can't exactly pussyfoot around that place. 

I really did like the direction they decided to go with her in Shadow Broker. Having her sort of reveal a little bit of her old self at the end was pretty clever and made me care about her a lot more than I did for the rest of ME2. The whole point of her character it seemed was to be vulnerable in ME1, and they managed to change that while still keeping her sympathetic in Shadow Broker. 
 
To be honest though, she isn't the strongest character in Mass Effect by far. Some of the writing isn't great, and sometimes the voice actress gets on my nerves with her delivery, but overall I liked the direction they went with her.

I thought she was great in both games.

I thought the change between 1 and 2 was a little far-fetched but I did like her a lot better in Shadow Broker.

" I really did like the direction they decided to go with her in Shadow Broker. Having her sort of reveal a little bit of her old self at the end was pretty clever and made me care about her a lot more than I did for the rest of ME2. The whole point of her character it seemed was to be vulnerable in ME1, and they managed to change that while still keeping her sympathetic in Shadow Broker.  To be honest though, she isn't the strongest character in Mass Effect by far. Some of the writing isn't great, and sometimes the voice actress gets on my nerves with her delivery, but overall I liked the direction they went with her. "

I thought she was pretty funny in the original, as well, when you'd ''talk'' to her mid mission and she'd comment on something related to the situation. I'll never forget when she implied she was getting a lot of sand up her ass crack during Virmire.. 
 
Overall she's one of my favourite ME companions and Shadow Broker strengthened that likeability all the more.

Yeah, I found her to be too needy in Mass Effect 1, but Mass Effect 2 in general made me regret choosing the space racist over her.

All I know is that in ME3 I'm staying with Tali, F Liara 

I have come to the conclusion that perhaps her personality hasn't flew straight off the wall its just I haven't read the book (or is this the comic) 
 
Anyone know the name of it?... they all have such vague names

It's a fair character arc, it's just unfortunate that most of Liara's development happens off-screen.  You can still see elements of her old personality at times though.  If you play a renegade Shep and have a relationship going on with Liara it works out pretty well: Liara appears to become a badass due to Shepard's influence and -at least in the relationship scenes- Shepard's character softens due to Liara's influence.  I was impressed; games rarely bother with regular character arcs, let alone attempting mirrored arcs.
 
The Liara/Shep scenes at the end of Shadow Broker (at least with Jen Hale at the mic) are some of the best in the series imo, and probably some of the best in gaming full stop.

" @johnnysasaki:  Feron's voiced by Yuri Lowenthal, best known over GB for voicing Yosuke in Persona 4, so no surprise he has a natural likeability for GBer's :P "

She changed for the good.
 
Bit more attitude, sure of herself yet still kinda fragile and whiny.
 
Just how I like my alien species!

I actually really like Liara, even though if I had to describe her - meek, nerdy 'good girl' alien-  she sounds like she would be annoying. I think I had more fun in Shadow Broker than in most of the actual missions in ME2 just because I got to chill with her again. I thought they did a good job of explaining why she would want to be take over as the SB (even though how she got into that business in the first place was a bit of a stretch). If she isn't in your party in ME3 I will be PISSED. 

Liara is Space Leliana.  Leliara.

I will always like Liara. She's probably my favorite female character in all of Mass Effect and she will always be my Shepards Companion.

I liked Liara a lot. Especially since I often teamed her up with Kaidan, which made her the harsher one of the two. Kaidan's such a puss!
I look forward to see what happens in ME3.. She's certainly a lot more badass since the Shadow Broker.

" The Liara/Shep scenes at the end of Shadow Broker (at least with Jen Hale at the mic) are some of the best in the series imo, and probably some of the best in gaming full stop. "

Unconcerned at this point, I'm staying with Lawson.  Who wants kids anyway?

I boned Tali in ME2 but kinda wish I stayed loyal to Liara. Really hoping it doesn't screw me over in ME3!

Liara was cool in ME1 because she was new to the hero business.  Now she's a full-fledged badass hero and she's even cooler.

I didn't really like Liara in the first game, nor her cold demeanor in the second. But in the DLC, she was a bit cooler.