While a great deal of the world was sitting, enthralled with the US political machinations, it appears that Twitter - the microblogging service with which many of us have a dysfunctional love-hate relationship - took the opportunity to roll out a new piece of functionality through its Japanese partners - called Twicco - and simultaneously remove a critical piece of functionality from Twitter for the rest of us.

The good news? Twitter now has that groups feature you've always wanted - if you happen to be located in Japan. The bad news? Hope you liked that last tweet, because there's no getting rid of it now.

Let's start with the positive part first: what Twitter has released in Japan. Seesmic's Loic LeMeur is reporting that Twitter Japan has just released the ability to follow groups on Twitter.

Twitter launches groups in Japan

As Loic says "So Twitter doesn't have groups in the US, but it does in Japan?" Yes, it would seem that way.

At first blush, the new group feature appears to be very similar to the "#hashtag" functionality that Twitter users have used to track conversations, combined with the ability to subscribe to that tag as one would via Twitter Search nee Summize. For an example of the group function in action, see the Twicco group on the iPhone.

Could this group functionality be a glimpse of a much-requested feature slated for the broader Twitter market? Only time will tell.

Now, the second part of the story. The part about "what Twitter taketh away."

Ever had a tweet that you regretted? Sure, we all have. And at that point, we simply went to the "trash can" icon to eliminate that errant missive. One click and the tweet was expunged from the permanent record.

But now? It appears that Twitter has removed the ability to delete tweets - and that includes both direct and public timeline tweets. No more trash can.

While no formal announcement has been made, Twitter users have been actively griping about the missing functionality. Clearly, people miss the ability to remove unwanted or duplicate tweets.

So, why delete delete? Good question. To save the fragile Twitter architecture? To make way for something new? To simply ensure that Twitter had the ability to withstand the US political turmoil?

At this point - with no official announcement - anything would be conjecture. That said, it's safe to assume that something is in the works, if only avoiding the re-emergence of the Fail Whale.

[Update] As of 10 AM Pacific time, November 5, delete has been restored. It appears that the functionality was temporarily suspended as part of the effort to ensure Twitter remained up during the US Presidential election coverage.