Depends on whether they have pooling rights under the lease. Typically, if there are no pooling rights and no wells have been drilled on the land, the lease will expire pursuant to its terms and you can then lease again to another outfit (or the same outfit) at current market rates. If the lease allows the driller to pool, they have you land tied up indefinetely because all they have to do is pool your property with another parcel with a well -- doesn't need to be a marcellus well, any old producing shallow well will do -- and the term of the lease will be extended so long as the well is producing gas. If it looks like that well will not be producing, they typically reserve the right to change the property you are pooled with to include a parcel that has a producing well. Long and the short of it is, if you did not delete the pooling provisions of their standard leases, you may never see a producing well on your land and will receive chump change in royalties possibly forever.
Regarding the Clean and Green question. My understanding is if you are part of a unit producing gas then your C&G status will be revoked. My lease says the gas company will pay any rollback and future tax increases.