Until recently Pachube has offered only its basic version (limited public feeds only, limited datastreams, etc,) as free. Now folks at Pachube decided to provide their whole service at no limits!
So the new quotas are:
|Private and Public feeds||Unlimited|
|Number of datastreams||Unlimited|
|Datapoint history storage||Unlimited|
|Datapoint bulk import||500 per API request|
|API usage limits||100 requests per minute|
More info here.