I am confused. 
What exactly is the Double Decker bus model that SMRT is
procuring? 
Is it just the 103 units of Alexander Dennis
Enviro500 (mentioned in a Facebook
post) or does it also
include around 100 units of MAN Lion's City
DD? 
Because according to http://publictransportsg.wordpress.com/2014/03/21/smrts-new-double-deck-buses/
- a rather credible source that has "predicted" many new bus routes
- it seems that SMRT is procuring Double Decker buses from two
brands (MAN and Alexander Dennis), instead of just that one brand
(Alexander Dennis) which we have (more) sources to confirm
it. 
If it is true that SMRT is procuring two models of Double Decker
bus, then this may explain why the dates vary in some
sources; Previously, someone
shared with me a picture of a SMRT tender document showing that the
Double Decker buses will be introduced in August 2014. This week,
SMRT say that the Double Decker buses will be introduced in June
2014. 
At first, I thought that SMRT
is accelerating the procurement process, thus they can introduce
the Double Decker buses in June 2014. Now that I have read this
article from http://publictransportsg.wordpress.com/2014/03/21/smrts-new-double-deck-buses/
, I think I know why there are two different dates: SMRT is
procuring two models of Double Decker bus. 
Therefore, instead of around 100 units, SMRT is actually
introducing around 203 units of Double Decker bus - by the end of
this year. 
Currently, according to Wikipedia, including the one with 'SMB' prefix,
SMRT has 324 units of Articulated bus. 
On the assumption that part of the around 203 units of Double
Decker bus will replace some units of Articulated bus, say 75% of
them (since BSEP is primarily about enhancing existing bus
services, then secondarily about adding new bus services), around
152 units of Articulated bus will be replaced with around 152 units
of Double Decker bus by the end of this year. 
But then again, I thought SMRT said that "while the
double-deckers will be useful for adding capacity on services into
the city, they are not as suitable for heavily-used feeder routes"
(http://ride.asiaone.com/news/general/story/smrt-get-double-deckers)
- which implies that it may continue to have Articulated buses in
its fleet? 
So, I guess SMRT wants to just reduce the composition of
Articulated buses in its fleet, and not totally replace them with
Double Decker buses. 
Could this be SMRT's only procurement of Double Decker buses at
this juncture, and there will be procurement of new Articulated
buses next year to replace the units of Articulated bus that would
remain next year? 
Please correct me if I am
wrong. 
There is nothing to correct or speculate.
Just take the buses as they come la.
The sources are credible?
I wonder.
I wouldn't read too much in people's attempts to wiggle
information where it should not be.