--DDL and some data:
create table Dates (
UserID int not null,
InDate date not null,
Weeks int not null);

insert into Dates (UserID,InDate, Weeks)
select 1,'8/31/2012',5 union
select 2,'9/14/2012',2;

--Expected results:
--UserID,OutDates
--1,9/7/2012
--1,9/14/2012
--1,9/21/2012
--1,9/28/2012
--1,10/5/2012
--2,9/21/2012
--2,9/28/2012

with cteTally(n) as (
select top (select max(d1.Weeks) from Dates d1)
    row_number() over (order by (select null)) as n
from
    sys.all_columns a
    cross join sys.all_columns b
)
select
    d.UserID,
    dateadd(wk, t.n, d.InDate) OutDates
from
    Dates d
    cross join cteTally t
where
    t.n <= d.Weeks
order by
    d.UserID,
    OutDates
;
go

drop table Dates;
go