Apple announced its second tablet last night and says 2011 will be "the year of the iPad 2". The £429 tablet goes onsale in the UK on 25 March sporting a slimmer 8.8mm profile, faster processor and much improved graphics.

However, whereas last year's iPad was making a new market; this year model is launching as one of hundreds. And while Apple boss Steve Jobs crowed at last night's iPad 2 launch that the current model accounts for 90 percent of the tablet market, the new model is going to be pitched against Windows-based devices that themselves enjoy market dominance.  

Apple's iPad accounts for a 90 percent share of the tablet market, but the march of the Android devices clearly has its maker rattled. At last night's iPad 2 launch, Steve Jobs was in bullish mood about the likely success of the iPad 2, which goes onsale in the US on 11 March on AT&T and Verizon, but acknowledged that the redesign and faster processor of the new model was a necessary step.

The Apple iPad 2 runs a 1GHz ARM dual-core A5 processor and will give the tablet a timely boost. Apple boss Steve Jobs says the iPad 2 is up to twice as fast as the current iPad model. Tablets based around the Google Android mobile operating system already run at 1GHz and while devices based on the dedicated Android Honeycomb tablet OS are only just going onsale, models such as the Samsung Galaxy Tab (which runs Android 2.1 for smartphones) have stolen noticeable market share from Apple.

From its position of strength last summer, when the iPad accounted for 95 percent of all tablet device sales, the iPad now holds 90 percent of the market according to Strategy Analytics. This is still impressive, but a cause for concern for Apple given that Motorola, RIM and HP are all launching tablets of their own in the coming weeks. Dell has just given its Streak tablet an update in the form of a 7in version, while Toshiba has licked its wounds after withdrawing its Folio tablet late last year and also has a second device set for imminent launch.

While Apple is rightly credited with creating the tablet market as we currently know it, there are plenty of technology fans who will prefer the familiarity of the Windows interface, or the open approach offered by the Android platform.

Another concern for Apple must surely be that the tablets the iPad are up against aren’t half bad. Primed with dual-core processors and expandable memory, plus the support for Adobe Flash that the iPad famously lacks, the tablet of 2011 is a desirable device in its own right. Some offer 3D gaming; all support the HD video output – a feature Jobs made much of last night when announcing a "mirrored screen" output cable for the iPad 2.

First impressions from tablets on show at both CES and Mobile World Congress in the past two months were extremely favourable.At this week's CeBit event, yet more tablets are being unveiled. Acer, Asus, MSI and HTC have all shown fully working tablets that most tech fans would be proud to call their own.

And while the iPad has been eagerly adopted by gadget fans and non-geeks, there's still some question over how good a business device the iPad is. HP and RIM are banking on success in this arena with their more business-focused tablets that run familiar office applications and, in the case of the BlackBerry Playbook, secure BBM messaging and encrypted email over the BlackBerry Enterprise Server.

All of which suggest to us that Apple couldn't afford not to rethink the iPad. Last year was emphatically the year of the iPad; this year, Apple is going to have to do a lot harder.