DotCloud vs Heroku

Can DotCloud dethrone Heroku?  It is getting more and more common for web applications to use more than one type of technology.  For example I have rolled out apps recently that incorporate some real-time updates powered by socket.io which runs on node.js.  I also have been using mongodb from the get-go on all my projects and skipping mysql/postgres altogether.  So, I was extremely impressed with how easy it was to setup an app on dotcloud.  Mongodb instance - done.  Ruby app - done.  Node.js app - done.  On Heroku this would have been impossible, or required some expensive 3rd party addons.
Here's the rundown of what I love about dotcloud.

1. It is very easy to mix and match your own technology stack
2. No git, no problem : I deployed my app from a dropbox folder!
3. Independence :  I wanted to make sure my mongodb database was getting backed up - on my own terms.  This was easy to do on dotcloud : http://snipplr.com/view/54805/dotcloud-mongodb-backup-script/ 
4. Quick support

However there are a few unknowns about dotcloud:

1. Reliability : I had a few issues getting my app running on ruby 1.8.7 as well as using a custom nginix.conf file.  With the broad array of technologies that dotcloud supports will they be able to make them all run smooth all the time?
2. Cost : It seems impossible to find out how much things are going to cost.

And here's why I love Heroku (my critical Ruby apps are going to stay there for the time being)

1. It's reliable.  I have never had a push to heroku blow up for reasons that weren't my fault.
2. It's simple.  Heroku does one (two if you count node.js) thing very well and that is host rails apps.

What I don't like about Heroku is how they push Add-Ons.  You always need an add-on ($$$).  I like to have a little more control over my app.  With dotcloud I feel like I have that control with the same simplicity of use and a whole lot more possibilities.
Watch out Heroku!