Number  Date          WW
392     2012-07-23    30
439     2012-07-24    30
735     2012-07-25    30
882     2012-07-26    30 *
193     2012-07-30    31
412     2012-07-31    31
425     2012-08-01    31
748     2012-08-02    31
711     2012-08-03    31 *
757     2012-08-07    32
113     2012-08-08    32 *
444     2012-08-15    33 *

882     30
711     31
113     32
444     33

select t1.number, t2.ww
from yourtable t1
inner join
(
    select max(date) mxdate, datepart(week, [Date]) ww
    from yourtable
    group by datepart(week, [Date])
) t2
    on t1.date = t2.mxdate
    and datepart(week, t1.[Date]) = t2.ww;

;with cte as
(
  select number, datepart(week, [Date]) ww,
    row_number() over(partition by datepart(week, [Date])
                      order by date desc) rn
  from yourtable
)
select number, ww
from cte
where rn = 1

declare @test table(Number int, Date datetime, WW int);

INSERT INTO @test
    (Number, Date, WW)
VALUES
    (392, '2012-07-22 17:00:00', 30),
    (439, '2012-07-23 17:00:00', 30),
    (735, '2012-07-24 17:00:00', 30),
    (882, '2012-07-25 17:00:00', 30),
    (193, '2012-07-29 17:00:00', 31),
    (412, '2012-07-30 17:00:00', 31),
    (425, '2012-07-31 17:00:00', 31),
    (748, '2012-08-01 17:00:00', 31),
    (711, '2012-08-05 17:00:00', 31),
    (757, '2012-08-06 17:00:00', 32),
    (113, '2012-08-07 17:00:00', 32),
    (444, '2012-08-14 17:00:00', 33)

SELECT * FROM (
select number, date, ww,
row_number() over (partition by ww order by date desc) rn
from @test) v
WHERE rn = 1;

SELECT number, [date]
FROM tablename T
WHERE NOT EXISTS (
    SELECT 1
    FROM tablename
    WHERE DATEPART(wk, [date]) = DATEPART(wk, T.[date])
        AND date > T.[date]
)