I apologize if this should be obvious or if it’s been discussed elsewhere. After Splat is no longer compatible with Windows and we are forced to move into a different DAW will included plugins like the Blue Tubes (does anyone use those), Cakewalk, Sonitius, The CA2A, console emulations, style dials etc be able to be used in other DAWs?

Here are some results that I found: http://forum.cakewalk.com/FindPost/3694963
 
Studio One, which I am testing, doesn't seem to support DX plugins, which leaves out a bunch of old -- but still useful -- Cakewalk bundled plugs. Most DAWs that you might switch to will bundle their own third party and proprietary plugins and instruments, so wherever you end up chances are you'll be able to keep working without buying a bunch of new stuff (I think Reaper is an exception to this). But some of the Cakewalk plugs are going to be hard to replace.
 
Note: None of this works if you don't keep your SONAR installed.
 
Good luck!

I've tested most of the SONAR plugins in Mixcraft, but if they work there they should work in Studio One as well. So far, the majority of them have proven to be portable, including all of my favorites (e.g. Channel Tools).
 
I won't list them all here, just the ones that aren't portable, as it's a shorter list:
 
Adaptive Limiter
Breverb
TH3
Bluetubes plugin collection

I'm finding that my beloved AAS Lounge Lizard Session Sonar Edition doesn't work in Studio One. 
Guess I'll have to upgrade.

Bitflipper - have you been able to get the Sonitus plugins to work?

No. I should have added all the DX effects to that list: Cyclone, Groove Player, TTS-1, and the Sonitus plugins. I was just thinking in terms of SONAR-tethered VSTs.
 
However, Craig A has been trying out a DX/VST wrapper that seems to be working for him in Studio One.
 
Someone has already reported that the Sonitus plugs work, but perhaps not all of them. Also the TTS-1, which is good news. I'll give it a try myself later today.
 
Update: yes, the Sonitus plugs work in Mixcraft with this wrapper. I have only tried my favorites so far: reverb, comp and delay. And yes, the TTS-1 works too. I placed dxshell.x64.dll and dxishell.x64.dll in \program files\acoustica mixcraft 8\vst\3rdParty and rescanned. All the goodies came up.

bitflipper - I found Craig's post before I saw your answer, and I can confirm about Studio One roughly the same results you are finding in Mixcraft. My attention span is too short to actually test all these plugins (I even have the audio VSTs from Vegas), but at least they show up in the S1 browser and the ones I tried do work, which gives me some hope that in the future the others will work, too, and I won't have to go on a spending spree to replace crucial plugs.

I’m sure this has been answered elsewhere but I can’t find it with search. How about the instruments like Dimension, Rapture etc... will they work in other DAW’s? I got the SSL bundle which I think will satisfy my console needs, I’m thinking about picking up J37 for my tape needs. I’m going to ride Sonar down as long as possible, just planning for the inevitable.

All of the VST instruments that were bundled with Sonar should work except for True Pianos and the three "Session" instruments from AAS. The unlocked versions of those AAS instruments are available for free to registered Focusrite hardware owners via their Plugin Collective program through December 8 (just a coincidence) or for half price currently as the Session Bundle from AAS.