It really is just a threat though. These companies use the appearance of a competitor to extract cheaper pricing from their suppliers. If anyone is expecting better than Netbook performance, they're probably out of their mind.
Dropping prices temporarily until a newcomer is strangled is something we've heard of in the past, but this time the competitor has a huge and growing mobile market, so the threat and lower prices are likely to stay around for a long time.
With current super bloated state of the web, Electron apps and other disasters? Probably all of them.