Not yet, but we are getting a constant stream of new announcments, meaning that 3rd party devs and publishers are jumping onto the Switch ship instead of jumping from the ship as they did with the Wii U after a couple of months.

The lack of big 3rd party games at launch was probably due to the failure of the Wii U, with the publishers, apart from Ubisoft, being very wary about the Switch. When they saw it's a success and that 3rd party games do pretty well, they started producing games for the console, too. But this is a delayed action, which will only translate into more games in the future, but makes it looks relatively bad right now, especially compared to Sony and Microsoft.

However, for both a Nintendo and a handheld hybrid console, the 3rd party support is already pretty good comparatively, and is bound to grow even further with the success the Switch is having.

The low power of the Switch compared to Xbox and Playstation might soon be a problem for simple ports, though, as the Switch can't nearly keep up with them in raw power. But with versions and spinoffs of games specifically made for the Switch, the 3rd party support will still grow. And then there's the prospect of a new hardware version in the future, which at least could bring the power close to XBO levels and thus could further push the support of 3rd party games by then.

No, it's not impressive yet. But neither was the support for Wii or WiiU six months in. It is, however, more impressive than for both those systems since it's obvious Nintendo is much more focused on creating strong relationsships with the likes of Sega, Bethesda. Electronic Arts and so on.

I don't remember hearing anybody say it was impressive before, so the wording on the title is a bit weird. I think the success of the Switch caught a lot of developers off-guard (eg. Capcom) so they're probably scrambling to make games now: will still take a couple years before we see the results though.

Wii U definitely on launch had better 3rd party support than Switch had, but we know that Wii U 3rd party support start dying only few months after launch, and only after 1 year Wii U almost completely left without 3rd party support.

Switch on other hand had just few smaller 3rd party games on launch, but completely opposite to Wii U it getting more and stronger 3rd party support how time passes.

Main reason why Wii U left whitout 3rd party support only after 1 year and why Switch is getting more and stronger 3rd party support how time is going, is beacuse Wii U had terible sales and it was obvous that console will not be succes so 3rd party start abonding Wii U very early, on other hand Switch has great sales and it's obvious that platform will be success, and that's why we have more and more 3rd party announcement. Also, after Wii U failed, some devs take "wait and see approach" with Switch, they wanted first to see if Switch will be failed similar to Wii U or it will successful console. So you dont need to be pesimistic about future Switch 3rd party support, it can be only stronger and stronger and I am sure we will have much more 3rd party ananucments next year comperd to this one.

Reason why maybe some people used word "impressive" is just because Bethesda already announced 3 AAA games while they didn't announce not single one for Wii and Wii U, telling us that Switch will have much more serious support than Wii and Wii U.

Not yet, but I feel like it might be breaking through soon specifically thanks to a strong launch plus developers like S-E and Bethesda. I think in a year or so you'll be looking at the following games either on Switch or announced:

DOOM
Skyrim
Wolfenstein II
Evil Within 1/2
Fallout 4
Final Fantasy XV: Switch Edition
Final Fantasy VII Remake
Kingdom Hearts III
Dragon Quest XI
Dragon Quest Builders 2
Grand Theft Auto V
LA Noire
Monster Hunter 5 SE (Switch Edition)
Madden NFL
FIFA
NHL
NBA 2K
WWE 2K
Call Of Duty
Yakuza (Sega)
Castlevania
Marvel Vs. Capcom Infinite

Assassin's Creed 

I think right now a lot of devs that were on the fence are greenlighting content because the system has gotten off to a good start.

I think it's perceived as good because it's exceeding expectations.
After the colossal commercial failure that is the Wii U, people are expecting very weak support from third parties from the get go. But so far we're getting nice surprises and that's what's getting us excited.

No, but at least it's not bad.

You are missing the point. LA Noire on a plane flight? Hell yeah

Well they should team up with more developers like Ubisoft. Mario + Rabbids: Kingdom Battle was absolutely amazing. I was not a fan of Hyrule Warriors, but I know many people really liked it. I think that would be a smart move.

The Wii U wasn't underpowered compared to PS360. Compare the Switch to the 3DS 3rd party support, you'll see a big difference.