As a multiple-times-a-day Aperture user for the last several years - I'm
really glad to hear this. Apple has made it abundantly clear, that they were longer going to invest any effort into Aperture, and so we're going to get the best of all worlds. The application is absolutely rock solid for me - most of the database crashes, and corruptions have stopped occurring for over a year - so in the interim, I have a product that works for me and will keep me satisfied for the next couple years.
Meanwhile, Apple is going to put all their energy into a single photo system, instead of trying to do some schizophrenic split between iPhoto/Aperture - I expect to see a pretty excellent system out of it.
Perhaps it's because I don't work commercial or event photography, but the reality is that most of what I use Aperture for these days could probably be done with a slightly beefier iPhoto - which is pretty much what Photos is going to become.
Photostream, as of about 3-4 months ago, has also gotten reliable enough that I never have to worry about any picture that I've taken being on my Laptop. Unlike the early days (months, year?) when it was pretty much a crapshoot as to whether your pictures would move from your iPhone to PhotoStream and then to your laptop - It Just Works now.
So, good news all around.