Well yes, but they're still read-only, not a big deal.
If they provided *write* APIs from day one, at least they could have started getting cross-posts from apps like Tweetdeck. Still, not really a big deal... people are living in Facebook and Twitter, some cross-post to LinkedIn but I wonder who ever reads statuses on it...
With read-only APIs people need to remember first, and then have to go there and do the post. Why bother? I guess they thought that everyone would move over because, well, because they are Google so people should be thrilled and move over. I would say they learnt nothing from Waves (bugs, too slow in delivering functionality, no killer-app, people got border instantly).
Also: logorrhea on Twitter is somehow mitigated by the maximum number of characters limit; the few people on G+ are producing petabytes of useless babbling.
It was good to build the launch around the "Circles" concept, but it's nothing new. It took an eye-blink from Facebook to revive their "Lists" concept and with the introduction of subscriptions, they put the last nail in the coffin.
Now, if only Facebook would build a Feed Reader as good as Goggle's one before the new "enhancements" (sic)... but I'm not holding my breath given they just killed RSS support :(