I'm a bit behind. I'm sorry. Too busy with preparations for our new house that we're moving to quite soon (I'm moving tomorrow in fact). Official Google Blog:
As someone who tests Google products daily, I know that the simplest solution is often the one that works best. In the case of online storage, whether it's a picture, a video or an email, you should just, well, be able to store it without having to worry about whether you've got enough space in each particular product. That's why the Picasa team is pleased to tell you that in a few hours we'll be rolling out extra storage that you can purchase to use across several Google products (today, Picasa Web Albums and Gmail; soon, other applications like Google Docs & Spreadsheets). That will help make storage really useful, like letting you upload lots of full resolution images to Picasa Web Albums.
When you reach the limit of free storage (i.e., 1GB for Picasa Web Albums, 2.8GB for Gmail), consider this your overflow solution. Plans start at $20/year for 6GB (yes, $5 cheaper than before), with larger plans ranging up to 250GB. If only testing everything were this easy.
What this means is two things: we can forget about unlimited storage for Gmail. A feature that Yahoo Mail has had for a while now. The second thing is that it won't be long until the Google Disk. Everything is place now, including a way to get storage that you can share across Google services.