Well, it's somewhat unclear since "GenuineIntel" and "Intel" are not quite the same. I'm betting a good lawyer could make the case that the first explicitly seeks to confuse the user and thus dilutes the trademark. It would be interesting to see this play out in court though. I wonder if the judge could actually tell them that by using their trademark in a technical sense like this, perhaps that would cause dilution itself.

As always, with the law it's a bit more complex than it might seem.

Also note that most browser UAs explicitly states "like X."