Well, I don't think this is a surprise to anyone.
Per a report by Alcatel-Lucent's Kindsight Security Labs (you can read it HERE.), Android malware has increased 6 fold to over 120,000. The bulk of these are Trojans of various sorts (the report gives you a breakout of the top ones).
And, sadly, this also shows the weakness of application signing to weed out the malware. We've already seen issues with Google's Bouncer keeping out the bad stuff, as well as what BlueBox recently found. (see my prior posts on both of these matters).
Related, they also show an increase in infected home networks. Again, not a big surprise if you think about it. Most people who setup home networks have little or no IT (much less IT Security) background.
For a good overview article, read THIS from Ziff-Davis.
Again, what I see here could be addressed by a couple of things.
1. Obviously Bouncer needs to be improved. BUT people can't rely upon it solely.
2. People need to be encouraged to install anti-malware apps on their smartphones. Ideally, just as with most PC that come preinstalled with a commercial AV program (usually with a set period of free use), we need to start seeing smartphones come pre-installed with SOME kind of anti-malware app. AND those people writing and putting out books/magazines on smartphones need to include security apps as part of their recommended installs people should have on their smartphones.