Before I get into this - thanks to both Fortis and frogbear for trying the list out. Glad you had fun. Well, assuming you did.
There were a number of oft-mentioned concerns with the past list. I thought about all of them fairly hard before I worked out 1.0b. I'll explain the changes, then address some of the concerns:
Heavy Support Option revised - two more Tarantulas, no Tarantula option:
Advised on the advice of (IIRC), nealhunt.
Fire Support option revised:
Again, nealhunt
Razorback option revised:
Should allow for ablativeness if necessary without promoting spamming.
Tarantula option revised:
Simplified.
Tarantulas are now Tarantula MkIs:
The versions that don't move so easily are, of course, the inferior MkIIs, which are constructed from heavier materials, lack the sophisticated grav-engines, and which had the carrying handles left off after cost overruns.
Mole Mortars and Thudd Guns have been combined into Field Guns (which are basically Thudd Guns):
The idea was to have them be usable more than anything else - they are. Beyond that, I'm not too worried, and this isn't the place to decide how a Mole Mortar should work anyway.
Removed Troop Insertion Thunderhawk:
I miss it a little, but it's not necessary, and there's enough stuff in this list as it is.
Now, people's concerns:
Lack of single Warhounds: The Space Marines aren't supposed to be a war-machine heavy army - their lack of them is one of their major weaknesses in fluff, and indeed is necessary for the security of the Imperium. War Machines in a Space Marine army would represent the commitment of significant forces by another organization. Also, no single Warhounds helps balance out some of the reduced prices on line units.
Inclusion of old units: One of the things I like most about 40K (and also Epic) is the multiplicity of possibilities in the background - things that once were and are no more, things that might still be, and the things that are now but-who-knows-for-how-long. I see no reason to tie the list to a particular iteration of the background when the background is ever shifting and it's simple to include multiple aspects.
That said, I also shouldn't hold the list hostage to them. As long as there's an option which allows for them, that's enough - and there is such an option.
Tac and Dev prices: For the moment, I have left them unchanged - the people who've done the most playing seem content with them for the moment, and it's not exactly a difficult change to make should it prove necessary. The list lacks Air Assaulting and single Warhounds - slightly cheaper line infantry seems unlikely to destabilize things too much.
Lack of list focus: Well now, this one's trickier to deal with. I've tried to focus it up a bit by eliminating the Troop Insertion Thunderhawk and scaling back the artillery.
What I basically hope for/expect from this list is that it should represent a Battle Company deployed to fight on the ground with support. Beyond that, I'm not particularly picky about how it goes about it. It should focus on Space Marines over anything else, and on infantry more than armor (though armor can still play a major role, and likely will have to). Beyond that, I'm not particularly concerned. It may fight like Guard. It may fight like Eldar. It may fight like Tau. As long as it can fight, I'm pleased.
Oh, and frogbear - artillery pieces don't seem to have mounted, at least not in other lists. If it seems to be a real problem, I suppose we could be trendsetters.