Gas and solid state lasers will probably be around for a long time, at least for specific applications.
Diodes may cover the entire visible spectrum soon enough (waiting on yellow?), but wavelength is only one aspect.
If you need a very precise bandwidth, or high pulse power, or anything like that, laser diodes cannot provide it. Surely you can build a 1 watt continous laser diode, but what if you needed an -average- of 1 watt, in the form of a megawatt pulse during 1 microsecond, each second? No way diodes can deliver that.
A different matter is what lasers will be available to the enthousiasts, and it may look a bit bleek in that department. Yes we are getting more and more nice direct diode wavelength, but also losing beam quality. Lasers for things like projectors and such usually are multimode.
The most affordable single mode diodes with some serious power came out of optical writing drives, dvd for red, bluray for 405 nm.
I think optical storage media in the form of discs will be gone from the consumer market in 10 years or so, as well as any newly made devices to write or even read them. The problem is that the largest capacity rewriteable bluray discs available is only 50 GB, and those discs cost over $10 each. SD cards are about twice as expensive per GB right now, but given all their other advantages (not the least being the size of a stamp instead of that of a frisbee) makes consumer use of optical disks already a thing of the past.
And yeah, if you purely look at the cost to store a terabyte of data, harddrives and ssd's are cheaper when you want a terabyte or more regardless... and still not as bulky as a bluray disc in it's jewel case.
One chance of high power single mode diodes staying available in consumer electronics would be the development of things like holographic optical storage, where you can store a large amount of data in a small volume.
Then again we may seem some complete novel application that yields us products to rip great lasers out off...

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Yes I agree on the beam quality I bought a Qisk 2 watt 450 NM unit small and burns through brown paper but the beam sucks it's' rectangular and not very nice and high divergence. kinda disappointing but if you want to burn stuff 12 inches or closer . it's the laser for you. but the beam is horrid