Nothing particularly new here. The option was already available in the advanced search page.

But now it's easier to use (more direct fiddling around with the results), and you can also decide to sort by relevancy or date (I believe that was not possible before).

Good point, but I don't think you can actually sort by date. Most likely, you can sort by date the top 1000 results or maybe even less. A search like: http://www.google.com/search?q=google&tbo=1&tbs=qdr:d,sbd:1 should display a lot of pages that are more recent than 20-30 minutes.

Was just about to say what Ionut Alex said. It's a cool find, but these are very old, I've used these exact queries (together with the 24 hour limit) for ages. In that light, I don't think that Google has done anything new here when it comes to real-time search everyone is buzzing about lately.

Sorting by date in combination with the time frame options may be new, though.

The "link:" is broken for me.
if you search for a domain name that has a hyphen in it, then results are garbage that have nothing to do with incomming links.

Example you say?
"link:br-online.de"
http://www.google.de/search?q=link%3Abr-online.de&hl=en&rlz=1B3GGGL_deDE220DE220&sa=N&output=search&tbs=qdr:d&tbo=1
First result in your "links 24h"-way has a "<br />" highlighted ;-)

I wrote a blogpost about it here:
http://www.stadtlich.de/blog/archives/39-link-operator-is-broken-in-google-with-a-hyphen-in-domainnames.html

look : not past 24 hours but past hours (1-2) : http://www.google.com/search?q=link%3Ablogoscoped.com&hl=en&client=firefox-a&rls=org.mozilla:en-US:official&hs=7Ex&sa=N&output=search&tbs=qdr:h

It's not just hyphenated domains, it's all of them. The link: command is treated as a text based search, not a special operator, when combined with the date based parameters. It has always been like this.

In many cases mentions of a domain name, especially those that are not keyword based, will also happen to have links to that domain, but that doesn't make it a link: search, just a mention one.

Phillip, you might want to update the post to reflect that. The blog search method is a real one though. :)

You can also export the Google webmaster tools external links report to excel and sort by date, although that just shows the last time the link was crawled, not necessarily the first time it was seen.

(Thanks Michael, I added an update!)