The build number disappeared from the lower right corner of my desktop. And now the System page says Win 10 Pro Insider Preview. It used to have the build number there as well as the old "name". I must have received an update?

Mine still has the build number.  There are two lines, your bottom line must have gotten covered up
 
Mine shows:
Windows 10 Pro Insider Preview
Evaluation Copy Build 10130
 
I just (now) checked for updates and there are no updates. 
 
However, build 10130 changed the identification on my multi-boot OS selection panel (I have a triple boot  Win7/8.1/10 each on separate hard drives).  It used to show Win 10 as Pre Release, it now just shows "Windows 10".

 D'oh ! The desktop thingy was hidden, but I swear Windows W had the build number.

It may well be that some of you are seeing updates that others aren't. After install, you can go to the Windows Update page and toward the bottom there is a combo box that allows you to choose the slow ring or the fast ring for update frequency. With the slow ring you receive updates to the OS infrequently, typically when a set of updates are more solidly baked. The fast ring exposes you to more potential problems but delivers updates much more quickly, sometimes every couple of days or so. The cool thing about the fast ring is that they often try out new feature and UI designs that don't always get approved for the slow ring based on feedback from users through the feedback tool.
 
As we get close to RTM I suspect we'll see fewer updates and the ones we do see will be less experimental in nature and more with a more release quality stability. I was on the fast ring till I moved my Windows 10 work from a virtual machine to my main machine, at which point I wimped out and set it to slow ring. Once I have a bit of confidence (and get some work done) I'll switch back. :) 

I'm on the "fast" setup.  There have been reports of leaked versions of later builds but no official release by Microsoft.
With the release date a month away, we may not see any additional (official) preview versions.  PC companies, such as Dell, HP, etc are probably already working on the RTM release for new PC's.
 
 

ok,  got it loaded on a VM at work.
 
It's...   interesting..   Sorta halfway between Win7 and Win 8.1

Yup a nice compromise IMO

RTM by end the of the month for manufacturers and developers. Release date for UK (maybe other countries) is 29th July.

Doktor Avalanche
RTM by end the of the month for manufacturers and developers. Release date for UK (maybe other countries) is 29th July.

Woo hoo! I'm a bit nervous about that because I think the lastest insider release (10130) is still pretty rough around the edges. I hope they've smoothed 'em out by then.

You have every right to be nervous. I personally would not touch it with a barge poll on my DAW installation until new year. Major bugs will be ironed out and driver support will be much better by then.