There’s probably a number of reasons why PC shipments stalled overall at the end of 2011. One of them could be the emergence of mobile devices like the iPad and several hundred different Android tablets. Another reason could be that there hasn’t been anything really exciting going on in the desktop space for some time.

Research firm Gartner shared numbers that showed a Q4 decline after two strong quarters before it. The drop was 1.4% among all vendors, and ended the year selling a total of 92.2 million units.

HP stayed on top of PC sellers at number one, but had a global dip of almost 16% compared to its shipments in 2010.

Here’s a similar study from IDC, broken into a global list and US only list:

Apple fared rather well in the US with an astounding 18% year over year growth, according to these numbers from IDC, even though they’re stuck at number three behind HP and Dell in the US.

Where will the PC market go from here? The introduction of Windows 8 should boost sales at some point this year, with new machines shipping with it pre-installed, but the first two quarters of this year should be fairly quiet thanks to the whisper-end to an otherwise strong 2011.

Sites like Sina Weibo, China’s largest micro-blogging website,  have been quick to capitalize on the void left by the blocking of Twitter by the Chinese government.

Projections suggest that there will be nearly 150 million micro blog users in the country by the end of next year.  This fact has been picked up by several major multi-nationals like Nokia, Dell and China’s own Lenovo who are already seeing the potential of micro blogs as an advertising platform and are using them to promote their products.

One example is Nokia’s October news briefings that were held completely on social networking websites, mainly in micro blogging services. Micro-bloggers could wear a 3D eyepiece to watch Nokia’s online 3D promotion video and interact with the company through its micro blog on Sina Weibo, .

“Micro blogs provide a new tool for us to interact with our potential consumers here in China,”  Yang Weidong, head of marketing for Nokia in China.

According to Nokia, at least 400,000 users ‘attended’ this online event wich resulted in more than 1,000 orders for Nokia’s N8 smartphone making the experiment a success for the company.

Another international company eyeing the potential for micro blog marketing is US computer manufacturer Dell which has already run successful campaigns on Twitter in America and has now set up its own micro blog on Sina Weibo that has received “hundreds of thousands” of visits and responses from Chinese micro-bloggers.