Then there is the tanking economy. ComScore just reported that Google's online ad revenue is falling. As businesses and consumers scale back their PC purchases, Microsoft's revenue from software licenses will drop as well. In a year, Microsoft will probably be looking at cost-cutting measures.
Given the source of ComScore data, I have some skepticism about its absolute accuracy. Still, it's hard to deny that the economy is headed in a nasty direction, and it seems logical that online advertising may take a hit. Google being the leader in that field, it would no doubt take the biggest financial hit. But MicroHoo won't be immune from a recession-fueled downturn either.
The past five years have provided a rising tide of online ad revenue that has lifted the Google boat a lot higher than Microsoft or Yahoo. If Microsoft and Yahoo couldn't succeed individually in a growing market, what scenario allows the combined MicroHoo to take Google market share away as it performs a painful business merger in a shrinking market?