Any information on pricing? I doubt they'd have specific prices ready to announce yet, but it would be good to at least know the DIMENSIONS by which it will be priced (e.g. per read and write, storage, etc?). Will it be accessible to "classic" App Engine front-end instances, or only meant for Compute Engine VM's and "App Engine 2.0" Managed VM's?
The biggest pain point with the current Datastore is how difficult it can be to predict your costs. Also, there are weird quirks in the pricing model (e.g. "writes" used to cost more than "reads", it's more expensive to delete rows than it is to flag them as tombstoned and continue storing them indefinitely, etc). These quirks have left people with a lot of technical debt from having designed around them.
If this is another database option (alongside the Datastore and CloudSQL) for "classic" App Engine apps, which aren't likely to be re-written for Managed VM's, then it might be interesting. However, if it's only for Compute Engine or Managed VM contexts, where you're not locked-in and are free to choose any technologies you want, then at this point I would need to hear some pretty amazing information on the pricing model before I could be bothered to even test it out. Google lock-in is painful... once you've gone through the trouble of breaking free from the App Engine jail, it's really difficult to even consider adding new lock-in dependencies.
EDIT: Doh. You have to click through a couple of links from the original post to find it, but they have indeed posted pricing specifics already.
Looks like it's priced by the number of VM nodes you want in your cluster, storage, and network I/O if you're using it from outside Google's datacenters. No metered pricing on "read ops" and "write ops". This model IS a significant improvement over classic Datastore pricing. Unfortunately, it doesn't look like you can use it as a Datastore-replacement on classic App Engine front-end instances... and I'm not sure that I wouldn't just use Cassandra in other contexts where I have complete control.
The biggest pain point with the current Datastore is how difficult it can be to predict your costs. Also, there are weird quirks in the pricing model (e.g. "writes" used to cost more than "reads", it's more expensive to delete rows than it is to flag them as tombstoned and continue storing them indefinitely, etc). These quirks have left people with a lot of technical debt from having designed around them.
If this is another database option (alongside the Datastore and CloudSQL) for "classic" App Engine apps, which aren't likely to be re-written for Managed VM's, then it might be interesting. However, if it's only for Compute Engine or Managed VM contexts, where you're not locked-in and are free to choose any technologies you want, then at this point I would need to hear some pretty amazing information on the pricing model before I could be bothered to even test it out. Google lock-in is painful... once you've gone through the trouble of breaking free from the App Engine jail, it's really difficult to even consider adding new lock-in dependencies.
EDIT: Doh. You have to click through a couple of links from the original post to find it, but they have indeed posted pricing specifics already.
https://cloud.google.com/bigtable/#pricing
Looks like it's priced by the number of VM nodes you want in your cluster, storage, and network I/O if you're using it from outside Google's datacenters. No metered pricing on "read ops" and "write ops". This model IS a significant improvement over classic Datastore pricing. Unfortunately, it doesn't look like you can use it as a Datastore-replacement on classic App Engine front-end instances... and I'm not sure that I wouldn't just use Cassandra in other contexts where I have complete control.