You mean Apple, Microsoft, Google, RIM et al?
Yes, I think it's a pretty fair assessment to say that they are all losing steam. Their basic problem is that smartphones and tablets have gone from being the cool new toys of yesteryear to being mainstream, expensive tools, with just a soupçon of "too clever for your own good".
I saw an interesting debate a few weeks ago on HN. Some people saw these generic tools as the future and specialised tools increasingly becoming obsolete. Other people saw the generic tools as Jacks-of-all-trades whose weaknesses next to dedicated mobile phones, music players, e-book readers, satnavs, etc. were becoming increasingly apparent as practical experience starts to trump the hype.
If I were brave enough to invest in hi-tech companies, I imagine I would be shorting all of the stocks I mentioned above right now. They are making a staggering amount of money today, to be sure. I'm just not sure how much all these new technologies they have been coming out with recently actually help real people to do things they care about, and I think they are highly vulnerable to indirect competition as consumers become more aware of what they actually care about and which gadgets help them do those things.
[Edit: Would the downvoter(s) care to explain why? Apple have or have recently had significant problems with the reliability of the iPhone 4, the spec for the iPad, and their reputation among the communities of app and content developers who support their entire infrastructure. Google have released a string of flops, many of which have been killed within a year, and are starting to look vulnerable even in their main playgrounds of search and on-line advertising, so unless something is fundamentally different in Android world there are probably similar difficulties there as well. RIM's last two big product launches have made Microsoft's handling of Vista look professional. Microsoft themselves have released a string of Windows Mobile platforms that have horrible reliability, functionality and performance compared to other major mobile operating systems. How are any of these companies not losing steam?]