I agree with Alan.B that you've got a pretty good way already figured out. I also agree with his comment about named columns, but I assume these are just for example.

There is another way that might be just a smidgen swifter, but you'd need to run a timing test to be sure. That is to use a Quirky Update.

SELECT [Object], [Date], status1, status2

INTO #Temp

FROM

(

SELECT [Object], status1=NULL, status2, [date]

FROM table2

UNION ALL

SELECT [Object], status1, NULL, [date]

FROM table1

) a;

DECLARE @status1 nvarchar(1000)

,@status2 nvarchar(1000);

ALTER TABLE #Temp ALTER COLUMN [Date] DATETIME NOT NULL;

ALTER TABLE #Temp ADD PRIMARY KEY([Date]);

UPDATE #Temp WITH(TABLOCKX)

SET @Status1 = Status1 = CASE WHEN Status1 IS NULL THEN @Status1 ELSE Status1 END

,@Status2 = Status2 = CASE WHEN Status2 IS NULL THEN @Status2 ELSE Status2 END

OPTION (MAXDOP 1);

SELECT * FROM #Temp ORDER BY [Object], [Date];

GO

DROP TABLE #Temp;

You should carefully read the section on the QU in this article: Solving the Running Total and Ordinal Rank Problems[/url] by Jeff Moden so that you understand the rules that apply when using the QU.

Initially I wrote that SQL 2012 might have a analytic function (LAG) that might make short work of this problem but I'm now not so sure, as an initial attempt didn't result in anything fruitful. There still could be a way I just don't have the time at the moment to play with it.