Which contract will be followed if we are asked to sign a new lease?

If the original lease was for 2 years and was signed in April, 2012 it does not expire until the end of March, 2014. If you sign a new lease it will supercede the old lease and bind you for 2 more years assuming it is a two year lease.

How does your 2 year lease expire in 1 year? If you want to leave you should talk with the landlord and see if you can agree on a move out day since it appears the landlord is changing the terms of your lease.

Probably. Make sure that the new contract says that it supersedes the original lease.

In Washington, a lease for longer than a year much be acknowledged with witnesses and seals for residential tenancies per RCW 59.18.210. When these formalities do not occur, a lease typically is treated as one of month-to-month. This does not mean the lease terms, other than the length of time, as not enforceable; they will be. Your lease may require that you give 30-days notice, or greater notice, but it cannot require you to give less than the statutory minimum of 20-days notice. Given your factual pattern, you may not technically have a lease, and if you choose to vacate, you are only required to provide the 20-days written notice before the end of a given rental period, unless otherwise agreed. This usually means you must serve your landlord with this notice by no later than the 9th or the 10th, depending upon whether there are 30 or 31 days in the month, and you must vacate by the end of that same month. You are not required to sign a new lease of you do not want to. If you do sign a new lease, and so long as it is for less than a year, that new lease will control over the old one. Usually the rules and rental terms are the same, the duration is all that has changed, however.

The new lease supersedes the old lease. Make sure the new lease says that it supersedes the old lease, just so there is no confusion.

It is the landlords error, sign the new agreement and argue you are month to month.

You need to point out to your landlord that the old lease has a year to run. If you had a typo and you signed it in 2011, you are probably better off going with the new lease. Otherwise, they can terminate you on 30 days notice.

I recommend you have an experienced landlord-tenant lawyer review both leases to give you a legal assessment. If you signed a 2-year lease in April 2012, it is unclear why said lease would expire in April 2013. The Wisconsin statutes provide that either party to a month-to-month tenancy can give a 28-day notice terminating tenancy, however, the tenancy only ends at the end of a rental period.

I believe the DE Landlord/Tenant Code states 60 day notice.