Acer and Hewlett Packard decided not to renew deal to implement Yahoo! search toolbar as default on its PCs. Carol Bartz tried to blow off that it wasn’t terribly important but she has a lousy poker face. If Yahoo’s search presence falls below 20%, you can start manning the lifeboats, people. Right now it’s at …. wait for it …. 20.6%. Bing is barely pushing 10%.