Sorry about this, I made some breaking changes to the page to fix an issue on mobile but forgot to make sure it still worked on desktop!
This is fixed as of the next build which should happen sometime in the next few hours. Thanks for the report!
I can confirm the behaviour but it isn't terminal.
If you click the "More sign up options" link and then click the "Sign up using Launchpad" link, you'll get a textbox that will pre-populate the OpenID box for you and will forward you onto Launchpad.
It's definitely a problem though. I'll punt this off to SE directly.
Update: It's been handed from SE mods ...
The way to get the link is:
Select your username (the avatar in the new not-technically black bar)
Click "My Logins"
Click "Add more logins..."
The answer to Can I (and How do I) use my askubuntu account on other Stack Exchange sites? is actually still correct, but Stack Exchange has changed their login page some so it isn't quite clear.
On the login page you need to click "more login options" and then input your launchpad URL in the OpenID field.
To add Launchpad login to your account, you can click this multi user link (works for who ever clicks it) to go to your profile and then click on "add more logins"
For more information you can see this page in the help center
Yes, it should.
However, you cannot use your Launchpad OAuth login on any site other than Ask Ubuntu. So you should also add either a StackExchange local login or a secondary login from, say, Google or Facebook, in order to authenticate to other sites (when cross-site cookies don't work or such).
I agree with Bruno Pereira that we should not make reputation on our site work like karma on Launchpad. Of course, you'd expect me to say that (I have over 60k rep, after all).
What I want to add is that I don't think the primary purpose of either reputation on our site or karma on Launchpad is -- or should be -- to incentivize participation. That is one of ...
You are absolutely right. Speaking prescriptively (rather than descriptively), you really should not need to publish your real-life identity as a prerequisite to serving as a moderator on a Stack Exchange site, or as a prerequisite to standing for election. There are many excellent Stack Exchange moderators who keep their Stack Exchange identity strictly ...
As Seth said you can use multiple login methods on StackExchange, one of them is OpenID and for example the link to your Launchpad profile. Launchpad and StackExchange however are completely independent and owned by different entities, they are not different products from one company where an employee can merge your accounts.
To help you with the question on why weren't all askubuntu accounts automatically linked to stackexchange, it is because, back when askubuntu was born, the stackexchange worked on common account systems (google, facebook) and their own stackexchange system. The launchpad for what I remember (Anyone please correct me if am wrong) was added later, but both ...