We're using API v1 to find any new tickets matching a custom view (aka filter) which works well.
API v2 looks like a great evolution, but it only allows filtering according to four pre-defined filters, with the error response (NB, errors much improved since v1!):
Should be a value in the list 'new_and_my_open,watching,spam,deleted'
Are you planning to open this up to allow either filtering by a custom view or more dynamic filtering in the parameters passed to the API?