yo tengosqlcmd.exe tanto de SQLServer 2008 como de SQLServer 2012:

PS C:\> Get-Command sqlcmd.exe

Definition
----------
C:\Program Files\Microsoft SQL Server\100\Tools\Binn\SQLCMD.EXE
C:\Program Files\Microsoft SQL Server\110\Tools\Binn\SQLCMD.EXE

Modificando$env:PATH fuerzo el uso desqlcmd.exe de SQL Server 2012:

PS C:\> $env:PATH = ($env:PATH -split ";" | Where-Object { $_ -notlike "*\Microsoft SQL Server\100\*" }) -join ";"
PS C:\> Get-Command sqlcmd.exe

Definition
----------
C:\Program Files\Microsoft SQL Server\110\Tools\Binn\SQLCMD.EXE

La instancia predeterminada de LocalDB está en funcionamiento y es propiedad del usuario actual:

PS C:\> sqllocaldb i v11.0
Name:               v11.0
Version:            11.0.2318.0
Shared name:
Owner:              DOMAIN\me
Auto-create:        Yes
State:              Running
Last start time:    12/06/13 18:17:57
Instance pipe name: np:\\.\pipe\LOCALDB#08EDBEF0\tsql\query

Ahora, puedo ejecutar el comando en(localdb)\v11.0 utilizandosqlcmd.exe

PS C:\> sqlcmd.exe -S "(localdb)\v11.0" -Q "select 1"

-----------
          1

Pero al intentar lo mismo conInvoke-Sqlcmd me sale un error de conexión:

PS C:\> Import-Module sqlps
PS C:\> Invoke-Sqlcmd -ServerInstance "(localdb)\v11.0" -Query "select 1"
Invoke-Sqlcmd : A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)

¿Qué puedo hacer para hacerInvoke-Sqlcmd conectar a(localdb)\v11.0 ?