It’s been nearly a week since Google Buzz was unveiled amid speculation it was going to be a Twitter and/or Facebook-killer. So, what is the buzz about Buzz now that people have had some time to use it?

In terms of sentiment, 42% of the conversations are positive, 44% are neutral and 14% are negative. This reflects the mixed reaction that Buzz has generated. Some people believe it’s a major strategic foray by Google into the world of social media, particularly because of the fact it’s built on top GMail, which has 175 million users/month. Jason Calacanis, a high-tech entrepreneur, for example, describes Buzz as “brilliant”.

This positive sentiment is tempered by people who are less than impressed with Buzz. Among the negative criticism is that Buzz doesn’t seem to have any compelling features that would prompt someone to leave Facebook and Twitter, or use them less often.

Steve Rubel, a well-known blogger and public relations executive, suggests that Buzz was created to protect GMail’s advertising revenue from Facebook, as opposed to Google looking to get into social media.

While Buzz attracted a lot of attention when it was launched on Feb. 9, the blogosphere’s interest has dropped off, perhaps because Buzz is not the out-the-gate smash-hit that many people expected.

As far as the leading keywords, GMail is at the centre of the most conversations. Not surprisingly, there are strong links to “Twitter” and “Facebook”, as well “network”.

Speaking of Twitter, Buzz has generated a lot of tweets in the past week – nearly 500,000, which isn’t surprising given Twitter users are likely enthusiastic users of Google services such as GMail and search.

What’s interesting – and different – about the conversations on Twitter is the amount of talk about privacy after people complained that Buzz was publicly disclosing their lists of followers and who they were following.

The launch earlier this week of Google Buzz has put the spotlight on the social media universe, and whether there’s an effective way to deal with the growing noise-to-signal ratio.

Among other things, Google Buzz may prompt some people to consider about their use of social media services, and whether there’s room in their “digital toolbox” for Google Buzz to sit along aside services such as Twitter, Facebook, LinkedIn, Ning and MySpace.

One of the big challenges facing Google Buzz is convincing people to give it a whirl when they’ve already got tools that provide much of the same functionality. While Google Buzz has some nice features, it might not be enough to get people to switch. It’s like getting Coca-Cola drinkers to try a new product from Pepsi that may just be the best soft-drink ever created.

In some respects, Google is a late-comer to the social media party even though its portfolio includes Blogger (blogging) and Orkut (social networking). To date, Google’s social media track record has been, at best, mediocre. For example, it purchase Jaiku a couple of years ago to get into the micro-blogging market, but Jaiku has pretty much disappeared from the scene.

As a result, Google is attempting to play catch-up by leapfrogging the competition. Google Buzz isn’t really an attempt to take on Facebook or Twitter but a move to provide social media users with a completely different experience that integrates all of your social media activity into a single “portal” – aka GMail.

It’s an ambitious project given that Facebook, Twitter, LinkedIn and MySpace have such large followings but using Google’s use of GMail as the platform to establish a beachhead makes a lot of sense.

For Google, the success of Google Buzz will depend on whether the features resonate with users who seem pretty content with what’s currently in their toolbox. If Google Buzz can offer a new and different social media experience, it might change the landscape in a major way.