Help me validate my micro mailing list idea?

So the frustration that led to the idea is that often times on social networks (twitter in my case) people say that they're going to do X thing that you are interested in (writing a tutorial, releasing a script/app/site, publishing a video, etc) and to check back soon, but it's near impossible to remember these kinds of things. I sometimes end up bookmarking the tweet and hoping that I'll eventually stumble into my bookmarks and see it, or remembering to check the user's feed every day for a bit until it's published or I forget.

So the solution would be a one-shot micro mailing list service. When you receive a lot of attention for something you said you will make/do you go to MySite, create a new "notification queue", give it a title & description, hit "generate link" and copy paste the link into the comments. Interested users then click on the link and are brought to the page on MySite where they see title & description and are prompted for their email address to receive the notification. When the OP then makes/does The Thing he goes to MySite, clicks on "notify" next to the relevant notification queue, inputs a body text (containing links/codes/whatever) and hits send. The subscribed people will then receive an email from MySite containing the body text.

It's a sort of platform-agnostic, no-code, one-shot mailing list for quickly notifying interested people. I think it would also be a good tool for indie devs to quickly validate interest in their ideas, right?