I think that train has already left. Ben has said many times over the past few years that he wants to get out of the image hosting business, and it looks like the gallery will finally go away for good now.
I am also officially going to pull the plug on the old Gallery software. It's way, way out of date, probably full of security holes, and generally a piece of junk. If you have any photos up there that are not backed up on your computer, please spend some time downloading them. I am looking at doing this sometime around summer.
If you don't want to host your pictures elsewhere, I really think it's best to just attach them to your posts. That way they will still be here in the future. If you look at old posts on this site, they are full of missing images from previous versions of the gallery software as well as files hosted offsite that are now gone.
That's right. There's many other free websites out there to share your photos that are much better than what I can cobble together. But if you don't want to do that then yes, just attach them to your posts.