LOOSE wire: Plaxo's Trojan Horse
Jeremy Wagstaff makes a pretty cogent argument that Plaxo's recent announcement that Yahoo! search will be built into their forthcoming version 2.0 toolbar shows that Plaxo's free business model was a classic Trojan Horse ploy. The idea that the new turf war for toolbars is Outlook makes a lot of sense to me.
I use enough add-ins that I have to decide whether I can afford the screen real estate some of these tools demand. I have a few tools installed whose toolbars I hide unless I need to access them.
LOOSE wire: Plaxo's Trojan Horse
Expect to see a lot more products that offer 'valuable services' via a toolbar in Outlook, but in fact are aimed at drawing traffic to certain sites. Browser toolbars are out; Outlook toolbars are in.