The raw numbers show how far Windows Phone has to go to catch up with iPhone (93.1 million in 2011) and Android (237.8 million). However, if you compare the same period in the product life cycle (i.e. the 12 month period after the quarter in which the initial product(s) launched) then the comparison is more favourable to Windows Phone (5.95 million for iOS and around 4 or 5 million for Android). Of course, that comparison makes the assumption that the context and circumstances around each platform launch was the same, which clearly they were not.
The early showing of Nokia is something of a surprise, given the very limited availability of Lumia products in Q4, but it does underline just how important the Microsoft - Nokia partnership is likely to be for the Windows Phone ecosystem.
Canalys' numbers are broadly in line with other source, although there are some differences. For example, in their report Canalys say that Nokia shipped 1.2 million Windows Phone devices, 600,000 MeeGo Harmattan devices and 17.8 million Symbian devices. Nokia in their own Q4 results said that more than 1 million Lumia devices had been sold to date (i.e. sales to January 26th), which would suggest Q4 sales of around 600,000 devices.
However, such differences are not unusual. It is important to differentiate between sales and shipments, which can vary (in either direction) depending on inventory decisions and logistics. For example, Nokia's Q4 shipments would likely be significantly higher than its sales as it is the company's very first quarter of Windows Phone device sales. More importantly all the numbers, especially those from third parties are only approximate. The numbers in such reports usually come from a combination of manufacturer's own data (e.g. quarterly reports) and channel inventory checks (i.e. asking a distributor how much they ordered or sold).