It’s hard to spring surprises in today’s technology industry, so Microsoft has set tongues wagging by inviting journalists to an event in Los Angeles on Monday for a “major” announcement. The speculation has quickly crystallised around tablets, although opinions differ on whether Microsoft will show its own device running the new Windows 8 OS, or focus more on partners. A Microsoft-manufactured tablet (or one made by a strong partner like Nokia) would be big news indeed. Cue ‘iPad-killer’ headlines, although ZDNet’s veteran Microsoft-watcher Mary-Jo Foley thinks the device may be more of a direct rival for Amazon’s Kindle Fire – a cheaper tablet with an emphasis on reading. In that case, the partner would surely be Barnes & Noble, given Microsoft’s recent $300m investment in its Nook business.