Very interesting! Google Chrome is blocked in some countries (Cuba, Syria, North Korea, Iran, and Sudan) :
Google says:

“In accordance with US export controls and economic sanctions regulations, we are unable to permit the download of Google Chrome in Cuba, Syria, North Korea, Iran, and Sudan.”

Think twice before switching browsers

1. It’s only in its first beta
2. You won’t have any add-ons
Add-ons are a huge draw for Firefox fans, and none of these are available in Chrome yet. Google does intend to create an API for such extensions, but for now you’ll have to make do without your AdBlocks, Better Gmails, and BugMeNots, or you’ll have to switch between browsers to use the add-ons you want when you want them.

3. You can’t synchronise
One big plus of Firefox is its ability to synchronise across multiple computers using Mozilla’s Weave option. This arrangement allows you to keep your home browser, your laptop browser and your work browser looking identical at all times and once you get used to that level of synchronisation, it’s hard to give up. Chrome doesn’t yet have that capability.
4. You may draw the short stick on standards
5. You’re giving advertisers extra ammo
6. The drop-down bar is dropped
7. You lose some history power

You can find more here pcadvisor.co.uk

Aditya K Sood from the EvilFingers community, which disclosed the first Chrome DoS vulnerability at the beginning of the month, has released a proof of concept demonstrating a memory exhaustion DoS vulnerability affecting Google’s Chrome versions Chrome/0.2.149.30 and Chrome/0.2.149.29 :

“The Google chrome browser is vulnerable to memory exhaustion based denial of service which can be triggered remotely.The vulnerability triggers when Carriage Return(\r\n\r\n) is passed as an argument to window.open() function. It makes the Google Chrome to generate number of windows at the same time thereby leading to memory exhaustion. The behavior can be easily checked by looking at the task manager as with no time the memory usage rises high. The problem lies in the handling of object and its value returned by the javascript function. Once it is triggered the pop ups are started generating. The Google Chrome browser generate object windows continuously there by affecting memory of the resultant system. Probably it can be crashed within no time. User interaction is required in this.”

More details on: zdnet.com