Personally I think the movement phase is the most important. All of the best players I have faced excel in this phase of the game. In 4th edition most transports were death traps so armies such as the 13th Company and Necrons had a big advantage since they could move long distances quickly without using transports. Both the Necron Lord with Veil of Darkness and the Rune Priest with Gate could teleport/deep strike anywhere on the table carrying a powerful unit along with them. Blood Angels was another army that could cover a lot of ground quickly due to strong jump infantry units such as Death Company and Honorguard... Death Company at one time could choose to rage as well for an additional d6 movement. I felt that Blood Angels was one of the fastest armies around.
The beauty of mech is twofold now in 5th, transports are resilient providing protection for your infantry plus you can cover up to twice as much ground as a foot slogging unit not accounting for running. Mech has hurt armies like Nidz and Necrons due to the resilience of mech. Landraiders are a true terror again. Everything seems to follow cycles. If these two armies are buffed up when they receive their new codices for 5th edition they could seriously affect the metagame... My prediction is that they will indeed.
It's hard for me to lay down simple tactics for the movement phase. There are a lot of variables. The role of a transport changes quite a bit depending on which army you play... tactical squads typically will sit in their rhinos and pillbox. Wyches in raiders want to move in and assault as soon as possible, same thing with boyz in trukkz and battlewagons. The monolith is probably the strangest transport in the game. I'm not a big fan of drop pods (except for dreadnaughts) and for the most part I think they have been played out plus they don't have an answer to the cheap Inquisitor/Mystics unit. On that note I would love to Inquisitor/Mystics removed as an allied choice for armies such as IG... they are too cheap for what they have to offer and to me that equals broken.
In terms of wargear I do think that dozer blades should be must have for transports... Dozer blades are typically very cheap as compared to extra armor. I only take extra armor for dreadnaughts and landraiders. The chances of immobilizing with dozer blades is 1 in 36 (6*6).