Calculate milliseconds iterativelly

Experts,

CREATE TABLE [dbo].[TimeStats]
(
	[TimingStatsID] [int] IDENTITY(1,1) NOT NULL,
	[TimingObject] [varchar](50) NOT NULL,
	[TimingStep] [int] NULL,
	[TimingBatch] [uniqueidentifier] NOT NULL,
	[Time] [datetime] NOT NULL
)

INSERT INTO [dbo].[TimeStats] VALUES ( 'gpmp', 1, '492939F4-611B-4BBC-9DF4-142F4AB774D9', '2014-02-07 13:56:56.533' )
INSERT INTO [dbo].[TimeStats] VALUES ( 'gpmp', 2, '492939F4-611B-4BBC-9DF4-142F4AB774D9', '2014-02-07 13:56:58.770' )
INSERT INTO [dbo].[TimeStats] VALUES ( 'gpmp', 3, '492939F4-611B-4BBC-9DF4-142F4AB774D9', '2014-02-07 13:57:01.420' )

INSERT INTO [dbo].[TimeStats] VALUES ( 'gpmp', 1, '95853BD6-7B77-4142-8E43-F4C528B67AF3', '2014-02-07 16:29:14.067' )
INSERT INTO [dbo].[TimeStats] VALUES ( 'gpmp', 2, '95853BD6-7B77-4142-8E43-F4C528B67AF3', '2014-02-07 16:29:14.640' )
INSERT INTO [dbo].[TimeStats] VALUES ( 'gpmp', 3, '95853BD6-7B77-4142-8E43-F4C528B67AF3', '2014-02-07 16:29:15.287' )

SELECT	*
		--, (TimingStep2 - TimingStep1 for each TimingBatch value) AS 'MS'
FROM	[dbo].[TimeStats]
ORDER BY	[TimingStep], [Time]

SELECT	'1' AS 'TimingStatsID', 'gpmp' AS 'TimingObject', '1' AS 'TimingStep', '492939F4-611B-4BBC-9DF4-142F4AB774D9' AS 'TimingBatch', '2014-02-07 13:56:56.533' AS 'Time', '2014-02-07 13:56:58.770 - 2014-02-07 13:56:56.533' AS 'Ms'
UNION ALL
SELECT	'4' AS 'TimingStatsID', 'gpmp' AS 'TimingObject', '1' AS 'TimingStep', '95853BD6-7B77-4142-8E43-F4C528B67AF3' AS 'TimingBatch', '2014-02-07 16:29:14.067' AS 'Time', '' AS 'Ms'
UNION ALL
SELECT	'2' AS 'TimingStatsID', 'gpmp' AS 'TimingObject', '2' AS 'TimingStep', '492939F4-611B-4BBC-9DF4-142F4AB774D9' AS 'TimingBatch', '2014-02-07 13:56:58.770' AS 'Time', NULL AS 'Ms'

DROP TABLE [dbo].[TimeStats]

Can anybody please help me out?

Thank You

Regards,

Kumar

Please do let us know your feedback. Thank You - KG, MCTS