working site install. you need to reverify the platform first.

db/db.drush.inc

@@ -186,7 +186,7 @@ class provisionService_db extends provisionService {
   function generate_site_credentials() {
     $creds = array();
     // replace with service type 
-    $db_type = drush_get_option('db_type');
+    $db_type = drush_get_option('db_type', 'mysql');
     // As of Drupal 7 there is no more mysqli type
     if (drush_drupal_major_version() >= 7) {
       $db_type = ($db_type == 'mysqli') ? 'mysql' : $db_type;
@@ -194,7 +194,7 @@ class provisionService_db extends provisionService {
 
     //TODO - this should not be here at all
     $creds['db_type'] = drush_set_option('db_type', $db_type, 'site');
-    $creds['db_host'] = drush_set_option('db_host', drush_get_option('db_host'), 'site');
+    $creds['db_host'] = drush_set_option('db_host', $this->remote_host, 'site');
     $creds['db_passwd'] = drush_set_option('db_passwd', provision_password(), 'site');
     $creds['db_name'] = drush_set_option('db_name', $this->suggest_db_name(), 'site');
     $creds['db_user'] = drush_set_option('db_user', $creds['db_name'], 'site');

platform/install.provision.inc

@@ -15,7 +15,7 @@
  * Check that we are trying to install a new site , and a new site only
  */
 function drush_provision_drupal_provision_install_validate() {
-  if (!drush_get_option('uri')) {
+  if (!d()->uri) {
     return drush_set_error("PROVISION_URL_REQUIRED", dt("You need to specify a valid url to install a site"));
   }
   if (_provision_drupal_site_exists()) {
@@ -52,7 +52,7 @@ function drush_provision_drupal_provision_install() {
  * If the install went south, and the site is not PROVISION_SITE_INSTALLED, clean up behind ourselves
  */
 function drush_provision_drupal_provision_install_rollback() {
-  if (drush_get_option('uri')) {
+  if (d()->uri) {
     if (!_provision_drupal_site_installed()) {
       _provision_recursive_delete('sites/' . drush_get_option('uri'));
     }

platform/provision_drupal.drush.inc

@@ -73,11 +73,6 @@ function _provision_context_init() {
   if (($context === 'platform' || $context === 'site') && drush_bootstrap_validate(DRUSH_BOOTSTRAP_DRUPAL_ROOT)) { 
     // i don't think i should be bootstrapping here yet ... but i have no choice yet.
     drush_bootstrap(DRUSH_BOOTSTRAP_DRUPAL_ROOT);
-    if ($context === 'site') {
-      drush_set_default('profile', 'default');
-      drush_set_default('language', 'en');
-      drush_set_default('aliases', array());
-    }
   }
 
   define('PROVISION_CONTEXT_SERVER', $context === 'server');
@@ -104,7 +99,6 @@ function provision_drupal_drush_exit() {
     if (PROVISION_CONTEXT_SITE) {
       if (drush_get_option('installed')) {
         drush_set_option('site_id', drush_get_option('site_id'), 'site');
-        drush_set_option('client_email', drush_get_option('client_email'), 'site');
         provision_save_site_data();
       }
     }

provision.environment.inc

@@ -38,8 +38,17 @@ function & d($name = NULL, $root_object = FALSE) {
 function provision_environment_factory($name) {
   $classes = array('server' => 'provisionServer', 'platform' => 'provisionPlatform', 'site' => 'provisionSite');
 
-  $options = drush_sitealias_get_record($name);
-  $type = isset($options['context_type']) ? $options['context_type'] : 'server';
+  $type = 'server';
+
+  $record = drush_sitealias_get_record($name);
+  $options = drush_get_context('options');
+
+  if (isset($record['context_type'])) {
+    $type = $record['context_type'];
+  }
+  elseif (isset($options['context_type'])) {
+    $type = $options['context_type'];
+  }
   $classname = $classes[$type];
 
   return new $classname($name);