Just for point of interest.
Applied:03/31/13
Conditional Approval- 05/03/13
Interview- 05/07/13 (<---yes I checked every 15 minutes for hours on end)
Approval- about 20 minutes after I saw the CBP agent.

Showed up early, and they saw me as soon as I walked in.
Asked for Drivers License (address verification), Birth Certificate, Passport
When talking to the CBP agent he mentioned to me to only use GE when leaving Pearson and that I could not participate in the program until I received the card which I was told to carry with me when I plan on using the machines. Hmmm. I didnt press him on this but I thought I could use GE as soon as I was approved.
Also they didnt (GE) sticker my passport- was told that they werent doing that anymore.

I don't have a sticker and been using it for a year. No need what so ever.

Why did they asked for birth certificate?

You must bring the following original documents to the enrollment center:

What do I need to bring for the interview? I'm thinking of just US passport.

How long does it take to be conditionally approved?
It's been 5 weeks since I've applied and my application is still "Pending review"

IIRC, mine took 6 weeks (maybe longer?). Others here have reported anything from ~3 weeks to ~8 weeks. You just have to be patient.

At my last four land crossings (driving Boston-Montreal and return twice, using the St. Armand/Highgate Springs crossing on I-89) I used the NEXUS card by itself as my entry document both ways. (For land/sea crossings you don't need a passport if you have a WHTI-compliant document, which the NEXUS card is.)

Going northbound, the NEXUS lane was open but both times I had passengers w/o NEXUS; I handed over my card and their passports, had the usual quick Q&A about guns, booze, etc with the CBSA officer, and went on our way. I didn't even have my passport in hand the first time; it was in my bag in the trunk!

Southbound was a similar experience (except that the NEXUS lane was closed): hand over my NEXUS and passengers' passports, answer questions, and drive on. No extra questions as far as I could tell, but it didn't seem to shorten the process either.

My recommendation: hand them just the NEXUS card. It is being used to cross the border, even if you're not using the special lane.

My understanding is that the nexus card can be used in lieu of a passport in either the non-nexus or nexus lanes - when crossing by land (or sea). However, both have to be used, whether using the nexus or non-nexus lines, when crossing by air.

That's correct, except you don't need your NEXUS card if you don't use NEXUS/GE when crossing by air.

After the interview do they give a temporary nexus pass? or do we need to wait for it in the mail before we can start using it for land crossing?

Nope. It'll be in the mail. It comes pretty quickly, though--less than a week, IME.

I don't know. It's definitely not on the list of required documents. They asked my family for ours when we interviewed five months ago. We didn't have them with us. We completed the interviews and then CBP told us that they wouldn't give us final approvals until we presented the birth certificates. We went home and I returned a few hours later with them. They photocopied and returned them. By the time I got back home our approval notifications were up on GOES.
Cards arrived in the mail a week later.

My guess is they were asked because they put them as documents in the application. IIRC, you are supposed to bring all documents that you listed on your application as proof of citizenship/residency(/whatever) to the interview so that the original copies can be verified (and be copied). I honestly can't remember what i was asked for in my initial or renewal interview.

On the other hand, better to bring them. It should take just a few minutes to gather and very little space to add them to a wallet/purse/bag. No big deal to just bring it in case you need them, and if you don't, no big deal either.

Great thread! One thing I'm sure is mentioned somewhere but I missed it is: When your account goes from pending review to conditional approval you do get an email!! I was checking my account randomly but no need, you get an email.

The tip regarding looking for cancellations was extremely helpful! Went from YEG date in September to May 17 to May 11!

Here is my timeline for anyone wondering:

Applied online: April 5, 2013
Conditional Approval: May 9, 2013
Interview: May 11, 2013
Approval: The US guy told me I was approved and I got the email as I was walking back to my car.

I applied with just my BC & DL as my passport expired 2 months ago. I was told to come back and provide my passport once I get a new one so they can add it, and there is a note on my account saying I have GE access, but need to add a passport to use it.

Probably the fastest change of status approval ^

Actually, I got my email confirming approval within a couple of minutes of walking out of the interview. I think that's pretty normal.